Process for Making Cyclohexanone

ABSTRACT

Disclosed are processes for making cyclohexanone from a mixture comprising phenol, cyclohexanone, cyclohexylbenzene, and an S-containing component, comprising a step of removing at least a portion of the S-containing component to reduce poisoning of a hydrogenation catalyst used for hydrogenating phenol to cyclohexanone.

PRIORITY CLAIM TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 62/140,702 filed Mar. 31, 2015; U.S. Provisional Application Ser.No. 62/057,919 filed Sep. 30, 2014; and European Application No.15151424.7 filed Jan. 16, 2015, the disclosures of which are fullyincorporated herein by their reference.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to U.S. Provisional Application Ser.No. 62/057,919 filed Sep. 30, 2014; U.S. Provisional Application Ser.No. 62/037,794 filed Aug. 15, 2014; U.S. Provisional Application Ser.No. 62/037,801 filed Aug. 15, 2014; U.S. Provisional Application Ser.No. 62/037,814 filed Aug. 15, 2014; and U.S. Provisional ApplicationSer. No. 62/037,824 filed Aug. 15, 2014, which are incorporated byreference.

FIELD

The present invention relates to processes for making cyclohexanone. Inparticular, the present invention relates to processes for makingcyclohexanone by phenol hydrogenation. The present invention is useful,e.g., in making cyclohexanone from cyclohexylbenzene oxidation andcyclohexylbenzene hydroperoxide cleavage.

BACKGROUND

Cyclohexanone is an important material in the chemical industry and iswidely used in, for example, production of phenolic resins, bisphenol A,ε-caprolactam, adipic acid, and plasticizers. One method for makingcyclohexanone is by hydrogenating phenol.

Currently, a common route for the production of phenol is the Hockprocess. This is a three-step process in which the first step involvesalkylation of benzene with propylene to produce cumene, followed byoxidation of cumene to the corresponding hydroperoxide, and thencleavage of the hydroperoxide to produce equimolar amounts of phenol andacetone. The separated phenol product can then be converted tocyclohexanone by a step of hydrogenation.

It is known from, e.g., U.S. Pat. No. 6,037,513, that cyclohexylbenzenecan be produced by contacting benzene with hydrogen in the presence of abifunctional catalyst comprising a molecular sieve of the MCM-22 typeand at least one hydrogenation metal selected from palladium, ruthenium,nickel, cobalt, and mixtures thereof. This reference also discloses thatthe resultant cyclohexylbenzene can be oxidized to the correspondinghydroperoxide, which can then be cleaved to produce a cleavage mixtureof phenol and cyclohexanone, which, in turn, can be separated to obtainpure, substantially equimolar phenol and cyclohexanone products. Thiscyclohexylbenzene-based process for co-producing phenol andcyclohexanone can be highly efficient in making these two importantindustrial materials. Given the higher commercial value of cyclohexanonethan phenol, it is highly desirable that in this process morecyclohexanone than phenol be produced. While this can be achieved bysubsequently hydrogenating the pure phenol product produced in thisprocess to convert a part or all of the phenol to cyclohexanone, a moreeconomical process and system would be highly desirable.

One solution to making more cyclohexanone than phenol from the abovecyclohexylbenzene-based process is to hydrogenate a mixture containingphenol and cyclohexanone obtained from the cleavage mixture to convertat least a portion of the phenol contained therein to cyclohexanone.However, because the phenol/cyclohexanone mixture invariably containsnon-negligible amounts of (i) S-containing component(s) that can poisonthe hydrogenation catalyst, and (ii) cyclohexylbenzene that can beconverted into bicyclohexane in the hydrogenation step, and becausehydrogenation of the phenol/cyclohexanone/cyclohexylbenzene mixture canalso lead to the formation of cyclohexanol, resulting in yield loss,this process is not without challenge.

As such, there is a need for an improved process for makingcyclohexanone from a mixture containing phenol, cyclohexanone,cyclohexylbenzene, and S-containing component(s).

The present invention satisfies this and other needs.

SUMMARY

It has been found that S-containing components contained inphenol/cyclohexanone mixtures can be effectively removed by using ananterior sorbent before the first distillation column for separatingcyclohexanone from the phenol/cyclohexanone mixture, and/or by using aposterior sorbent after the first distillation column but before thehydrogenation reactor, thereby alleviating the poisoning of thehydrogenation catalyst.

In a first aspect, the present disclosure relates to a process formaking cyclohexanone, the process comprising: (Ia) providing a crudemixture comprising cyclohexanone, phenol, cyclohexylbenzene, and anS-containing component; (Ib) contacting the crude mixture with ananterior sorbent capable of removing at least a portion of theS-containing component to obtain a first mixture comprisingcyclohexanone, phenol, and cyclohexylbenzene; (Ic) feeding the firstmixture into a first distillation column; (II) obtaining from the firstdistillation column: a first upper effluent comprising cyclohexanone ata concentration higher than the first mixture; a first middle effluentcomprising phenol at a concentration higher than the first mixture,cyclohexanone, cyclohexylbenzene, and bicyclohexane; and a first lowereffluent comprising cyclohexylbenzene at a concentration higher than thefirst mixture; (III) providing hydrogen and at least a portion of thefirst middle effluent as at least a portion of a hydrogenation feed to ahydrogenation reaction zone; (IV) contacting the hydrogenation feed withhydrogen in the hydrogenation reaction zone where phenol reacts withhydrogen in the presence of a hydrogenation catalyst under hydrogenationreaction conditions to obtain a hydrogenation reaction productcomprising cyclohexanone at a concentration higher than thehydrogenation feed, phenol at a concentration lower than thehydrogenation feed, cyclohexylbenzene, and bicyclohexane; and (V)feeding at least a portion of the hydrogenation reaction product intothe first distillation column.

In a second aspect, the present disclosure relates to a process formaking cyclohexanone, the process comprising: (I) feeding a firstmixture comprising cyclohexanone, phenol, cyclohexylbenzene, and anS-containing component into a first distillation column; (II) obtainingfrom the first distillation column: a first upper effluent comprisingcyclohexanone at a concentration higher than the first mixture; a firstmiddle effluent comprising phenol at a concentration higher than thefirst mixture, cyclohexanone, cyclohexylbenzene, bicyclohexane, and aportion of the S-containing component; and a first lower effluentcomprising cyclohexylbenzene at a concentration higher than the firstmixture; (III) removing at least a portion of the S-containing componentfrom the first middle effluent to obtain a hydrogenation feed; (IV)feeding at least a portion of the hydrogenation feed and hydrogen into ahydrogenation reaction zone where phenol reacts with hydrogen in thepresence of a hydrogenation catalyst under hydrogenation reactionconditions to obtain a hydrogenation reaction product comprisingcyclohexanone at a concentration higher than the hydrogenation feed,phenol at a concentration lower than the hydrogenation feed,cyclohexylbenzene, and bicyclohexane; and (V) feeding at least a portionof the hydrogenation reaction product into the first distillationcolumn.

In a specific embodiment of either the first or the second aspect of theprocesses of the present invention, both an anterior removal mechanismand a posterior removal mechanism are employed to remove at least aportion of the S-containing component from the hydrogenation feed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a process/system for makingcyclohexanone from a first mixture comprising phenol, cyclohexanone andcyclohexylbenzene including a first distillation column T1, ahydrogenation reactor R1, and a cyclohexanone purification column T2.

FIG. 2 is a schematic diagram showing a portion of a process/systemsimilar to the process/system shown in FIG. 1, but comprising modifiedfluid communications between and/or within the first distillation columnT1 and the hydrogenation reactor R1.

FIG. 3 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1 and 2, but comprising modified fluidcommunications and/or heat transfer arrangement between and/or withinthe first distillation column T1 and the cyclohexanone purificationcolumn T2.

FIG. 4 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1 to 3, but comprising a tubular heatexchanger-type hydrogenation reactor R1, where the hydrogenationreaction occurs primarily in vapor phase.

FIG. 5 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1 to 4, but comprising threehydrogenation reactors R3, R5, and R7 connected in series, where thehydrogenation reaction occurs primarily in liquid phase.

FIG. 6 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1 to 5, but comprising modified fluidcommunications between and/or within the first distillation column T1and the hydrogenation reactor R1.

FIG. 7 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1 to 6, but comprising an anteriorsorbent bed T4 before the first distillation column T1 configured forremoving at least a portion of the S-containing components from thephenol/cyclohexanone/cyclohexylbenzene feed fed to the firstdistillation column T1 to reduce or prevent catalyst poisoning in thehydrogenation reactor.

FIG. 8 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1 to 7, comprising a posterior sorbentbed T5 after the first distillation column T1 configured for removing atleast a portion of the S-containing components from thephenol/cyclohexanone/cyclohexylbenzene feed fed to the hydrogenationreactor to reduce or prevent catalyst poisoning in the hydrogenationreactor.

FIG. 9 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1 to 8, comprising a sorbent bed T6after the cyclohexanone purification column T2, configured to reduceamounts of S-containing components from the final cyclohexanone product.

DETAILED DESCRIPTION

Various specific embodiments, versions and examples of the inventionwill now be described, including preferred embodiments and definitionsthat are adopted herein for purposes of understanding the claimedinvention. While the following detailed description gives specificpreferred embodiments, those skilled in the art will appreciate thatthese embodiments are exemplary only, and that the invention may bepracticed in other ways. For purposes of determining infringement, thescope of the invention will refer to any one or more of the appendedclaims, including their equivalents, and elements or limitations thatare equivalent to those that are recited. Any reference to the“invention” may refer to one or more, but not necessarily all, of theinventions defined by the claims.

In the present disclosure, a process is described as comprising at leastone “step.” It should be understood that each step is an action oroperation that may be carried out once or multiple times in the process,in a continuous or discontinuous fashion. Unless specified to thecontrary or the context clearly indicates otherwise, each step in aprocess may be conducted sequentially in the order as they are listed,with or without overlapping with one or more other step, or in any otherorder, as the case may be. In addition, one or more or even all stepsmay be conducted simultaneously with regard to the same or differentbatch of material. For example, in a continuous process, while a firststep in a process is being conducted with respect to a raw material justfed into the beginning of the process, a second step may be carried outsimultaneously with respect to an intermediate material resulting fromtreating the raw materials fed into the process at an earlier time inthe first step. Preferably, the steps are conducted in the orderdescribed.

Unless otherwise indicated, all numbers indicating quantities in thepresent disclosure are to be understood as being modified by the term“about” in all instances. It should also be understood that the precisenumerical values used in the specification and claims constitutespecific embodiments. Efforts have been made to ensure the accuracy ofthe data in the examples.

However, it should be understood that any measured data inherentlycontain a certain level of error due to the limitation of the techniqueand equipment used for making the measurement.

As used herein, the indefinite article “a” or “an” shall mean “at leastone” unless specified to the contrary or the context clearly indicatesotherwise. Thus, embodiments comprising “a light component” includeembodiments where one, two or more light components exist, unlessspecified to the contrary or the context clearly indicates that only onelight component exists.

A “complex” as used herein means a material formed by identifiedcomponents via chemical bonds, hydrogen bonds, and/or physical forces.

An “operation temperature” of a distillation column means the highesttemperature liquid media inside the column is exposed to during normaloperation. Thus, the operation temperature of a column is typically thetemperature of the liquid media in the reboiler, if the column isequipped with a reboiler.

The term “S-containing component” as used herein includes all compoundscomprising sulfur.

In the present application, sulfur concentration in a material isexpressed in terms of proportion (ppm, weight percentages, and the like)of the weight of elemental sulfur relative to the total weight of thematerial, even though the sulfur may be present in various valenciesother than zero. Sulfuric acid concentration is expressed in terms ofproportion (ppm, weight percentages, and the like) of the weight ofH₂SO₄ relative to the total weight of the material, even though thesulfuric acid may be present in the material in forms other than H₂SO₄.Thus, the sulfuric acid concentration is the total concentration ofH₂SO₄, SO₃, HSO₄ ⁻, and R—HSO₄ in the material.

As used herein, “wt %” means percentage by weight, “vol %” meanspercentage by volume, “mol %” means percentage by mole, “ppm” meansparts per million, and “ppm wt” and “wppm” are used interchangeably tomean parts per million on a weight basis. All “ppm” as used herein areppm by weight unless specified otherwise. All concentrations herein areexpressed on the basis of the total amount of the composition inquestion. Thus, the concentrations of the various components of thefirst mixture are expressed based on the total weight of the firstmixture. All ranges expressed herein should include both end points astwo specific embodiments unless specified or indicated to the contrary.

In the present disclosure, a location “in the vicinity of” an end (topor bottom) of a column means a location within a distance of a*Hc fromthe end (top or bottom) of the column, where Hc is the height of thecolumn from the bottom to the top, and a1≦a≦a2, where a1 and a2 can be,independently: 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09,0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, aslong as a1<a2. For example, a location in the vicinity of an end of acolumn can have an absolute distance from the end (top or bottom) of atmost D meters, where D can be 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5,1.0, 0.8, 0.5, 0.4, 0.3, 0.2, 0.1, or 0.

An “upper effluent” as used herein may be at the very top or the side ofa vessel such as a distillation column or a reactor, with or without anadditional effluent above it. Preferably, an upper effluent is drawn ata location in the vicinity of the top of the column. Preferably, anupper effluent is drawn at a location above at least one feed. A “lowereffluent” as used herein is at a location lower than the upper effluent,which may be at the very bottom or the side of a vessel, and if at theside, with or without additional effluent below it. Preferably, a lowereffluent is drawn at a location in the vicinity of the bottom of thecolumn. Preferably, a lower effluent is drawn at a location below atleast one feed. As used herein, a “middle effluent” is an effluentbetween an upper effluent and a lower effluent. The “same level” on adistillation column means a continuous segment of the column with atotal height no more than 5% of the total height of the column.

Nomenclature of elements and groups thereof used herein are pursuant tothe Periodic Table used by the International Union of Pure and AppliedChemistry after 1988. An example of the Periodic Table is shown in theinner page of the front cover of Advanced Inorganic Chemistry, 6^(th)Edition, by F. Albert Cotton et al. (John Wiley & Sons, Inc., 1999).

As used herein, the term “methylcyclopentanone” includes both isomers2-methylcyclopentanone (CAS Registry No. 1120-72-5) and3-methylcyclopentanone (CAS Registry No. 1757-42-2), at any proportionbetween them, unless it is clearly specified to mean only one of thesetwo isomers or the context clearly indicates that is the case. It shouldbe noted that under the conditions of the various steps of the presentprocesses, the two isomers may undergo isomerization reactions to resultin a ratio between them different from that in the raw materialsimmediately before being charged into a vessel such as a distillationcolumn.

As used herein, the generic term “dicyclohexylbenzene” (“DiCHB”)includes, in the aggregate, 1,2-dicyclohexylbenzene,1,3-dicylohexylbenzene, and 1,4-dicyclohexylbenzene, unless clearlyspecified to mean only one or two thereof. The term cyclohexylbenzene,when used in the singular form, means mono substitutedcyclohexylbenzene. As used herein, the term “C12” means compounds having12 carbon atoms, and “C12+ components” means compounds having at least12 carbon atoms. Examples of C12+ components include, among others,cyclohexylbenzene, biphenyl, bicyclohexane, methylcyclopentylbenzene,1,2-biphenylbenzene, 1,3-biphenylbenzene, 1,4-biphenylbenzene,1,2,3-triphenylbenzene, 1,2,4-triphenylbenzene, 1,3,5-triphenylbenzene,and corresponding oxygenates such as alcohols, ketones, acids, andesters derived from these compounds. As used herein, the term “C18”means compounds having 18 carbon atoms, and the term “C18+ components”means compounds having at least 18 carbon atoms. Examples of C18+components include, among others, dicyclohexylbenzenes (“DiCHB,”described above), tricyclohexylbenzenes (“TriCHB,” including all isomersthereof, including 1,2,3-tricyclohexylbenzene,1,2,4-tricyclohexylbenzene, 1,3,5-tricyclohexylbenzene, and mixtures oftwo or more thereof at any proportion). As used herein, the term “C24”means compounds having 24 carbon atoms.

As used herein, the term “light component” means compound having anormal boiling point (i.e., boiling point at a pressure of 101,325 Pa)lower than cyclohexanone. Examples of the light component include, butare not limited to: (i) methylcyclopentanone; (ii) water; (iii)hydrocarbons comprising 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms,including but not limited to linear, branched linear, cyclic,substituted cyclic, alkanes, alkenes, and dienes; (iv) oxygenates suchas alcohols, aldehydes, ketones, carboxylic acids, ethers, and the like,of hydrocarbons; (v) N-containing compounds, such as amines, amides,imides, NO₂— substituted compounds, and the like; (vi) S-containingcompounds, such as sulfides, sulfites, sulfates, sulfones, and the like.It has been found that S-containing compounds, N-containing compounds,dienes, alkenes, cyclic alkenes, and cyclic dienes, and carboxylic acidscomprising 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms can be present in thephenol/cyclohexanone mixture produced by hydroperoxide cleavagereactions described in greater detail below, and they can beparticularly detrimental to the performance of the hydrogenationcatalyst, leading to catalyst poisoning and undesirable, prematurecatalyst performance reduction.

The term “MCM-22 type material” (or “material of the MCM-22 type” or“molecular sieve of the MCM-22 type” or “MCM-22 type zeolite”), as usedherein, includes one or more of:

-   -   molecular sieves made from a common first degree crystalline        building block unit cell, which unit cell has the MWW framework        topology. A unit cell is a spatial arrangement of atoms which if        tiled in three-dimensional space describes the crystal        structure. Such crystal structures are discussed in the “Atlas        of Zeolite Framework Types,” Fifth Edition, 2001, the entire        content of which is incorporated as reference;    -   molecular sieves made from a common second degree building        block, being a 2-dimensional tiling of such MWW framework        topology unit cells, forming a monolayer of one unit cell        thickness, desirably one c-unit cell thickness;    -   molecular sieves made from common second degree building blocks,        being layers of one or more than one unit cell thickness,        wherein the layer of more than one unit cell thickness is made        from stacking, packing, or binding at least two monolayers of        one unit cell thickness. The stacking of such second degree        building blocks can be in a regular fashion, an irregular        fashion, a random fashion, or any combination thereof; and    -   molecular sieves made by any regular or random 2-dimensional or        3-dimensional combination of unit cells having the MWW framework        topology.

Molecular sieves of the MCM-22 type include those molecular sieveshaving an X-ray diffraction pattern including d-spacing maxima at12.4±0.25, 6.9±0.15, 3.57±0.07, and 3.42±0.07 Angstrom. The X-raydiffraction data used to characterize the material are obtained bystandard techniques such as using the K-alpha doublet of copper asincident radiation and a diffractometer equipped with a scintillationcounter and associated computer as the collection system.

Materials of the MCM-22 type include MCM-22 (described in U.S. Pat. No.4,954,325), PSH-3 (described in U.S. Pat. No. 4,439,409), SSZ-25(described in U.S. Pat. No. 4,826,667), ERB-1 (described in EuropeanPatent No. 0293032), ITQ-1 (described in U.S. Pat. No. 6,077,498), ITQ-2(described in International Patent Publication No. WO97/17290), MCM-36(described in U.S. Pat. No. 5,250,277), MCM-49 (described in U.S. Pat.No. 5,236,575), MCM-56 (described in U.S. Pat. No. 5,362,697), andmixtures thereof. Other molecular sieves, such as UZM-8 (described inU.S. Pat. No. 6,756,030), may be used alone or together with the MCM-22type molecular sieves as well for the purpose of the present disclosure.Desirably, the molecular sieve used in the catalyst of the presentdisclosure is selected from (a) MCM-49; (b) MCM-56; and (c) isotypes ofMCM-49 and MCM-56, such as ITQ-2.

The process and systems for making cyclohexanone disclosed herein can beadvantageously used for making cyclohexanone from any feed mixturecomprising phenol, cyclohexanone and cyclohexylbenzene. While the feedmay be derived from any process or source, it is preferably obtainedfrom the acid cleavage of a mixture comprising cyclohexylbenzenehydroperoxide and cyclohexylbenzene, which, in turn, is preferablyobtained from aerobic oxidation of cyclohexylbenzene, which, in turn, ispreferably obtained from benzene hydroalkylation. Steps of thesepreferred processes are described in detail below.

Supply of Cyclohexylbenzene

The cyclohexylbenzene supplied to the oxidation step can be producedand/or recycled as part of an integrated process for producing phenoland cyclohexanone from benzene. In such an integrated process, benzeneis initially converted to cyclohexylbenzene by any conventionaltechnique, including oxidative coupling of benzene to make biphenylfollowed by hydrogenation of the biphenyl. However, in practice, thecyclohexylbenzene is desirably produced by contacting benzene withhydrogen under hydroalkylation conditions in the presence of ahydroalkylation catalyst whereby benzene undergoes the followingReaction-1 to produce cyclohexylbenzene (CHB):

Alternatively, cyclohexylbenzene can be produced by direct alkylation ofbenzene with cyclohexene in the presence of a solid-acid catalyst suchas molecular sieves in the MCM-22 family according to the followingReaction-2:

Side reactions may occur in Reaction-1 or Reaction-2 to produce somepolyalkylated benzenes, such as dicyclohexylbenzenes (DiCHB),tricyclohexylbenzenes (TriCHB), methylcyclopentylbenzene, unreactedbenzene, cyclohexane, bicyclohexane, biphenyl, and other contaminants.Thus, typically, after the reaction, the hydroalkylation reactionproduct mixture is separated by distillation to obtain a C6 fractioncontaining benzene, cyclohexane, a C12 fraction containingcyclohexylbenzene and methylcyclopentylbenzene, and a heavies fractioncontaining, e.g., C18s such as DiCHBs and C24s such as TriCHBs. Theunreacted benzene may be recovered by distillation and recycled to thehydroalkylation or alkylation reactor. The cyclohexane may be sent to adehydrogenation reactor, with or without some of the residual benzene,and with or without co-fed hydrogen, where it is converted to benzeneand hydrogen, which can be recycled to the hydroalkylation/alkylationstep. Depending on the quantity of the heavies fraction, it may bedesirable to either (a) transalkylate the C18s such as DiCHB and C24ssuch as TriCHB with additional benzene or (b) dealkylate the C18s andC24s to maximize the production of the desired monoalkylated species.

Details of feed materials, catalyst used, reaction conditions, andreaction product properties of benzene hydroalkylation, andtransalkylation and dealkylation can be found in, e.g., the followingcopending, co-assigned patent applications: U.S. Provisional PatentApplication Ser. No. 61/972,877, entitled “Process for MakingCyclohexylbenzene and/or Phenol and/or Cyclohexanone;” and filed on Mar.31, 2014; U.S. Provisional Patent Application Ser. No. 62/037,794,entitled “Process and System for Making Cyclohexanone,” and filed onAug. 15, 2014; U.S. Provisional Patent Application Ser. No. 62/037,801,entitled “Process and System for Making Cyclohexanone,” and filed onAug. 15, 2014; U.S. Provisional Patent Application Ser. No. 62/037,814,entitled “Process and System for Making Cyclohexanone,” and filed onAug. 15, 2014; U.S. Provisional Patent Application Ser. No. 62/037,824,entitled “Process and System for Making Cyclohexanone,” and filed onAug. 15, 2014; U.S. Provisional Patent Application Ser. No. 62/057,919,entitled “Process for Making Cyclohexanone,” and filed on Sep. 30, 2014;U.S. Provisional Patent Application Ser. No. 62/057,947, entitled“Process for Making Cyclohexanone,” and filed on Sep. 30, 2014; and U.S.Provisional Patent Application Ser. No. 62/057,980, entitled “Processfor Making Cyclohexanone,” and filed on Sep. 30, 2014, the contents ofall of which are incorporated herein by reference in their entirety.

Oxidation of Cyclohexylbenzene

In the oxidation step, at least a portion of the cyclohexylbenzenecontained in the oxidation feed is converted tocyclohexyl-1-phenyl-1-hydroperoxide, the desired hydroperoxide,according to the following Reaction-3:

The cyclohexylbenzene freshly produced and/or recycled may be purifiedbefore being fed to the oxidation step to remove at least a portion of,among others, methylcyclopentylbenzene, olefins, phenol, acid, and thelike. Such purification may include, e.g., distillation, hydrogenation,caustic wash, and the like.

In exemplary processes, the oxidation step may be accomplished bycontacting an oxygen-containing gas, such as air and various derivativesof air, with the feed comprising cyclohexylbenzene. For example, astream of pure O₂, O₂ diluted by inert gas such as N₂, pure air, orother O₂-containing mixtures can be pumped through thecyclohexylbenzene-containing feed in an oxidation reactor to effect theoxidation.

The oxidation may be conducted in the absence or presence of a catalyst,such as a cyclic imide type catalyst (e.g., N-hydroxyphthalimide).

Details of the feed material, reaction conditions, reactors used,catalyst used, product mixture composition and treatment, and the like,of the oxidation step can be found in, e.g., the following copending,co-assigned patent applications: U.S. Provisional Patent ApplicationSer. Nos. 61/972,877, entitled “Process for Making Cyclohexylbenzeneand/or Phenol and/or Cyclohexanone;” and filed on Mar. 31, 2014; U.S.Provisional Patent Application Ser. No. 62/037,794, entitled “Processand System for Making Cyclohexanone,” and filed on Aug. 15, 2014; U.S.Provisional Patent Application Ser. No. 62/037,801, entitled “Processand System for Making Cyclohexanone,” and filed on Aug. 15, 2014; U.S.Provisional Patent Application Ser. No. 62/037,814, entitled “Processand System for Making Cyclohexanone,” and filed on Aug. 15, 2014; U.S.Provisional Patent Application Ser. No. 62/037,824, entitled “Processand System for Making Cyclohexanone,” and filed on Aug. 15, 2014; U.S.Provisional Patent Application Ser. No. 62/057,919, entitled “Processfor Making Cyclohexanone,” and filed on Sep. 30, 2014; U.S. ProvisionalPatent Application Ser. No. 62/057,947, entitled “Process for MakingCyclohexanone,” and filed on Sep. 30, 2014; and U.S. Provisional PatentApplication Ser. No. 62/057,980, entitled “Process for MakingCyclohexanone,” and filed on Sep. 30, 2014, the contents of all of whichare incorporated herein by reference in their entirety.

Cleavage Reaction

In the cleavage reaction, at least a portion of thecyclohexyl-1-phenyl-1-hydroperoxide decomposes in the presence of anacid catalyst in high selectivity to cyclohexanone and phenol accordingto the following desired Reaction-4:

The cleavage product mixture may comprise the acid catalyst, phenol,cyclohexanone, cyclohexylbenzene, and contaminants.

The acid catalyst can be at least partially soluble in the cleavagereaction mixture, is stable at a temperature of at least 185° C. and hasa lower volatility (higher normal boiling point) than cyclohexylbenzene.

Feed composition, reaction conditions, catalyst used, product mixturecomposition and treatment thereof, and the like, of this cleavage stepcan be found in, e.g., the following copending, co-assigned patentapplications: U.S. Provisional Patent Application Ser. No. 61/972,877,entitled “Process for Making Cyclohexylbenzene and/or Phenol and/orCyclohexanone;” and filed on Mar. 31, 2014; U.S. Provisional PatentApplication Ser. No. 62/037,794, entitled “Process and System for MakingCyclohexanone,” and filed on Aug. 15, 2014; U.S. Provisional PatentApplication Ser. No. 62/037,801, entitled “Process and System for MakingCyclohexanone,” and filed on Aug. 15, 2014; U.S. Provisional PatentApplication Ser. No. 62/037,814, entitled “Process and System for MakingCyclohexanone,” and filed on Aug. 15, 2014; U.S. Provisional PatentApplication Ser. No. 62/037,824, entitled “Process and System for MakingCyclohexanone,” and filed on Aug. 15, 2014; U.S. Provisional PatentApplication Ser. No. 62/057,919, entitled “Process for MakingCyclohexanone,” and filed on Sep. 30, 2014; U.S. Provisional PatentApplication Ser. No. 62/057,947, entitled “Process for MakingCyclohexanone,” and filed on Sep. 30, 2014; and U.S. Provisional PatentApplication Ser. No. 62/057,980, entitled “Process for MakingCyclohexanone,” and filed on Sep. 30, 2014, the contents of all of whichare incorporated herein by reference in their entirety.

Separation and Purification

A portion of the neutralized cleavage reaction product can then beseparated by methods such as distillation. In one example, in a firstdistillation column after the cleavage reactor, a heavies fractioncomprising heavies (such as amine sulfuric acid complex, which can beregarded as an amine sulfate salt, if an organic amine is used toneutralize at least a portion of the sulfuric acid present in thecleavage reaction product before it is fed into the first distillationcolumn) is obtained at the bottom of the column, a side fractioncomprising cyclohexylbenzene is obtained in the middle section, and anupper fraction comprising cyclohexanone, phenol, methylcyclopentanone,and water is obtained.

The separated cyclohexylbenzene fraction can then be treated and/orpurified before being delivered to the oxidation step. Since thecyclohexylbenzene separated from the cleavage product mixture maycontain phenol and/or olefins such as cyclohexenylbenzenes, the materialmay be subjected to treatment with an aqueous composition comprising abase and/or a hydrogenation step as disclosed in, for example,WO2011/100013A1, the entire contents of which are incorporated herein byreference.

In one example, the fraction comprising phenol, cyclohexanone, and watercan be further separated by simple distillation to obtain an upperfraction comprising primarily cyclohexanone and methylcyclopentanone anda lower fraction comprising primarily phenol, and some cyclohexanone.Cyclohexanone cannot be completely separated from phenol without usingan extractive solvent due to an azeotrope formed between these two.Thus, the upper fraction can be further distillated in a separate columnto obtain a pure cyclohexanone product in the vicinity of the bottom andan impurity fraction in the vicinity of the top comprising primarilymethylcyclopentanone, which can be further purified, if needed, and thenused as a useful industrial material. The lower fraction can be furtherseparated by a step of extractive distillation using an extractivesolvent (e.g., sulfolane, and glycols such as ethylene glycol, propyleneglycol, diethylene glycol, triethylene glycol, and the like) describedin, e.g., co-assigned, co-pending patent applications WO2013/165656A1and WO2013/165659, the contents of which are incorporated herein byreference in their entirety. An upper fraction comprising cyclohexanoneand a lower fraction comprising phenol and the extractive solvent can beobtained. In a subsequent distillation column, the lower fraction canthen be separated to obtain an upper fraction comprising a phenolproduct and a lower fraction comprising the extractive solvent.

Where an acid, such as sulfuric acid, is used as the catalyst in thecleavage step, and a liquid amine is used as the neutralizing agent toneutralize at least a portion of the acid before the cleavage productmixture is fed into the first distillation column, the acid will reactwith the amine to form a complex that is fed into the first distillationcolumn as well. It had been hoped that given the high boiling point ofthe complex, it would stay in the bottom fraction of the firstdistillation column, and therefore all sulfur would be removedcompletely from the bottoms of the first distillation column. However,in a very surprising manner, it has been found that sulfur was presentin the fraction comprising cyclohexanone and phenol exiting the firstdistillation column.

Without intending to be bound by a particular theory, it is believedthat the complex between the acid catalyst and the organic amine, ifpresent in the feed to the first distillation column, can decompose atleast partially in the first distillation column, due to the highoperating temperature therein (i.e., the highest temperature the liquidmedia is exposed to in the first distillation column, typically in thevicinity of the bottom of the column and/or in the reboiler) of at least120° C. (even 130° C., 140° C., 150° C., 160° C., 170° C., 180° C., 190°C., 200° C., 210° C., 220° C., 230° C., 240° C., or even 250° C.) isused, necessitated by the separation of cyclohexylbenzene presenttherein at high concentrations (e.g., at least 5 wt %, or 10 wt %, or 15wt %, or 20 wt %, or 25 wt %, or 30 wt %, or 35 wt %, or 40 wt %, or 45wt %, or even 50 wt %, based on the total weight of the cleavage productmixture), which has a very high normal boiling temperature (240° C.,compared to the normal boiling temperature of cumene of 152° C.). Thedecomposition of the complex likely produces, among others, SO₃, whichcan easily travel upwards along the first distillation column to upperlocations, where it can recombine at least partially with water to formH₂SO₄. This operation temperature can be significantly higher than thedistillation temperature the mixture of cumene, phenol, and acetone isexposed to in the first distillation column in the cumene process formaking phenol and acetone.

Thus, the presence of acid, especially strong acid such as SO₃, HSO₄ ⁻,R—HSO₄, and/or sulfuric acid in the first distillation column, cancatalyze many undesirable side reactions between and among the manycomponents present in the distillation mixture, leading to the formationof byproducts and/or premature malfunction of the distillation column.Furthermore, at high operation temperature, prolonged exposure to theacid can cause significant corrosion to the column equipment. The acidspecies can also make their way into the various fractions drawn fromthe different locations of the first distillation column, causingdifferent problems in subsequent steps where the fractions are furtherprocessed. If the acid species and/or S-containing component enter intoa down-stream hydrogenation reactor (described below) where phenol ishydrogenated to make additional cyclohexanone, the hydrogenationcatalyst can be easily deactivated.

Therefore, treating the cleavage product mixture before it enters intothe first distillation column using a solid-phase basic materialaccording to the present invention is highly advantageous and desirable.Doing so would reduce or eliminate the presence of acid species in mediainside the first distillation column, avoid undesirable side reactionsand byproducts formed as a result of contact with the acid species,reduce corrosion of the first distillation column caused by the acidspecies and the associated repair and premature replacement, and preventundesirable side reactions and byproduct formation in subsequent steps.

Such basic materials useful for the present invention, advantageously insolid-phase under the operation conditions, can be selected from (i)oxides of alkali metals, alkaline earth metals, and zinc; (ii)hydroxides of alkali metals, alkaline earth metals, and zinc; (iii)carbonates of alkali metals, alkaline earth metals, and zinc; (iv)bicarbonates of alkali metals, alkaline earth metals, and zinc; (v)complexes of two or more of (i), (ii), (iii), and (iv); (vi) solidamines; (vii) ion-exchange resins; and (viii) mixtures and combinationsof two or more of (i), (ii), (iii), (iv), (v), (vi), and (vii). Oxides,hydroxides, carbonates and bicarbonates of alkali and alkaline earthmetals and zinc can react with acid to form salts thereof, whichpreferably, are also in solid-phase under the operation conditions.Preferably, an ion exchange resin is used. Such ion exchange resinpreferably comprise groups on the surface thereof capable of adsorbingand/or binding with protons, SO₃, HSO₄ ⁻, H₂SO₄, complexes of sulfuricacid, and the like. The ion exchange resin can comprise a strong and/ora weak base resin. Weak base resins primarily function as acidadsorbers. These resins are capable of sorbing strong acids with a highcapacity. Strong base anion resins can comprise quarternized amine-basedproducts capable of sorbing both strong and weak acids. Commercialexamples of basic ion exchange resins useful in the present inventioninclude but are not limited to: Amberlyst® A21 basic ion exchange resinavailable from Dow Chemical Company.

Desirably, as a result of the treatment of the cleavage product mixtureusing the present invention, substantially all sulfur and/or acid isremoved from the cleavage product mixture before being fed into thefirst distillation column. Thus, the feed supplied to the firstdistillation column may exhibit one or more of the following traits (i),(ii), (iii), (iv), and (v):

(i) total acid concentration, based on the total weight of the mixturefed into the first distillation column, of at most 50 ppm, such as nohigher than 40 ppm, 30 ppm, 20 ppm, 10 ppm, 8 ppm, 6 ppm, 5 ppm, 4 ppm,3 ppm, 2 ppm, or even 1 ppm;

(ii) total sulfuric acid concentration, based on the total weight of themixture fed into the first distillation column, of at most 50 ppm, suchas no higher than 40 ppm, 30 ppm, 20 ppm, 10 ppm, 8 ppm, 6 ppm, 5 ppm, 4ppm, 3 ppm, 2 ppm, or even 1 ppm;

(iii) total sulfur concentration, based on the total weight of themixture fed into the first distillation column, of at most 50 ppm, suchas no higher than 40 ppm, 30 ppm, 20 ppm, 10 ppm, 8 ppm, 6 ppm, 5 ppm, 4ppm, 3 ppm, 2 ppm, or even 1 ppm;

(iv) total acid concentration in the feed supplied to the firstdistillation column is at most 10%, or 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%,or even 1%, of the total acid concentration in the cleavage productmixture prior to being treated by using the method of the presentinvention; and

(v) total sulfur concentration in the feed supplied to the firstdistillation column is at most 10%, or 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%,or even 1%, of the total sulfur concentration in the cleavage productmixture prior to being treated by using the method of the presentinvention.

Cleavage of cyclohexylbenzene hydroperoxide in a media comprisingcyclohexylbenzene hydroperoxide, cyclohexanone, phenol, andcyclohexylbenzene typically uses acid catalyst, such as sulfuric acid,at concentrations higher than in the cleavage of cumene hydroperoxide ina media comprising cumene hydroperoxide, phenol, acetone, and cumene.Thus, in cyclohexylbenzene hydroperoxide cleavage, sulfuric acidconcentration in the media can range from, e.g., 50 (or 60, 80, 100,150, 200, 250, 300, 350, 400, 450, 500) ppm to 2000 (or 1800, 1600,1500, 1400, 1200, 1000, 800, 600) ppm, based on the total weight of thecleavage reaction media. If an organic amine is used to neutralize theacid in the cyclohexylbenzene hydroperoxide cleavage product mixture, alarge quantity of the amine would be consumed, which would representquite substantial costs to the overall process. In the presentinvention, either inexpensive solid-phase bases such as hydroxides,carbonates and bicarbonates (e.g., NaOH, KOH, Na₂CO₃, NaHCO₃, CaCO₃, andthe like), or regenerable ion exchange resins, can be used, therebyreducing the overall costs to the process. Furthermore, where a largequantity of amine is used, a large quantity of amine acid complexmaterial would be produced and delivered to the first distillationcolumn. Even at relatively low distillation column operation temperaturewhere only a very small percentage of the complex decomposes, because ofthe large quantity of the complex supplied to the first distillationcolumn, a non-negligible quantity of SO₃, HSO₄ ⁻, R—HSO₄ and/or H₂SO₄may nonetheless be produced and travel along the column to the variousfractions drawn from the column. Therefore, using the process of thepresent invention to treat cleavage product mixture comprising acid at ahigh concentration to remove substantially all of the acid before thefirst distillation column is particularly advantageous.

Total sulfur concentration in the organic media can be determined byusing conventional methods such as gas chromatography followed by massspectrometry (GC-MS), liquid chromatography, ICP-AES, ICP-MS, and thelike. For example, total sulfur measurement techniques may include ASTMStandard Test Method D 5504: Determination of Sulfur Compounds inNatural Gas and Gaseous Fuels by Gas Chromatography andChemiluminescence; ASTM D 5623: Sulfur Compounds in Light PetroleumLiquids by Gas Chromography and Sulfur Selective Detection; ASTM D 7011:Determination of Trace Thiophene in Refined Benzene by GasChromatography and Sulfur Selective Detection; and ASTM D5453 StandardTest Method for Determination of Total Sulfur in Light Hydrocarbons,Spark Ignition Engine Fuel, Diesel Engine Fuel, and Engine Oil byUltraviolet Fluorescence. Total sulfur measurement instruments mayinclude those utilizing the principles of Energy Dispersive X-RayFluorescence, (Pulsed) Ultra Violet Fluorescence ((P)UVF), and SulfurChemiluminescence Detection (SCD), for example utilizing the combustionof sulfur compounds to form sulfur monoxide (SO) and thechemiluminescence reaction of SO with ozone (O3), and otherpyro-fluorescence and pyro-chemiluminescence technologies.

Sulfuric acid concentration in the organic media can be determined byusing conventional methods such as titration, gas chromatographyfollowed by mass spectrometry (GC-MS), liquid chromatography, ICP-AES,ICP-MS, and the like. Sulfuric acid concentration may be derived fromthe measured total sulfur concentration, or vice versa.

Total sulfur concentration in the organic media can be determined byusing conventional methods such as gas chromatography followed by massspectrometry (GC-MS), liquid chromatography, ICP-AES, ICP-MS, and thelike.

After treatment using the method of the present invention, both totalacid concentration and acid precursor concentration in the feed suppliedto the first distillation column can be exceedingly low. Accordingly,the first distillation column can be operated at a high operationtemperature, such as temperatures higher than the disassociationtemperatures of complex materials formed between the acid catalyst usedin the cleavage step, such as sulfuric acid, and the following organicamines: (i) pentane-1,5-diamine; (ii) 1-methylhexane-1,5-diamine; (iii)hexane-1,6-diamine; (iv) 2-methylpentane-1,5-diamine; (v) ethylenediamine; (vi) propylene diamine; (vii) diethylene triamine; and (viii)triethylene tetramine, without the concern of issues associated withacid produced from thermal dissociation thereof under such highoperation temperature.

Separation and Hydrogenation

At least a portion, preferably the entirety, of the neutralized cleavageeffluent (cleavage reaction product), may be separated and aphenol-containing fraction thereof can be hydrogenated to covert aportion of the phenol to cyclohexanone in accordance with the presentinvention.

It has been found that hydrogenation catalyst used for hydrogenatingphenol to make additional quantities of phenol is highly susceptible topoisoning by S-containing components and/or acids in the feed to thehydrogenation reactor. As such, it is highly desirable that acids and/orS-containing components are removed from the feed fed into thehydrogenation reactor.

Examples of the separation and hydrogenation process and/or system areillustrated in the attached drawings and described in detail below. Itshould be understood that process and/or systems shown in the schematic,not-to-scale drawings are only for the purpose of illustrating thegeneral material and/or heat flows and general operating principles. Tosimplify illustration and description, some routine components, such aspumps, valves, reboilers, pressure regulators, heat exchangers,recycling loops, condensers, separation drums, sensors, rectifiers,fillers, distributors, stirrers, motors, and the like, are not shown inthe drawings or described herein. One having ordinary skill in the art,in light of the teachings herein, can add those components whereappropriate.

FIGS. 1, 2, 3, 4, 5, 6, and 9 illustrate processes and systems that donot include an anterior or posterior sorbent beds before or after thefirst distillation column for separating cyclohexanone from phenol forthe purpose of poison removal from the hydrogenation feed. Nonetheless,because these drawings show systems and processes on which the presentinvention is based, they are included and described herein.

FIG. 1 is a schematic diagram showing a process/system 101 for makingcyclohexanone from a mixture comprising phenol, cyclohexanone andcyclohexylbenzene including a first distillation column T1 (i.e., thefirst distillation column), a hydrogenation reactor R1, and acyclohexanone purification column T2 (i.e., the second distillationcolumn). Feed 103 from storage S1, comprising phenol, cyclohexanone, andcyclohexylbenzene, is fed into the first distillation column T1.

Feed 103 can be produced by any method. A preferred method is bycleaving a cyclohexylbenzene hydroperoxide in the presence of an acidcatalyst such as sulfuric acid and cyclohexylbenzene as described above.Feed 103 may further comprise impurities other than cyclohexylbenzenesuch as: hydrogenation catalyst poisons; light components (definedabove) such as water, methylcyclopentanone, pentanal, hexanal, benzoicacid, and the like, and heavy components such asmethylcyclopentylbenzene, bicyclohexane, sulfate of an organic amine(such as 1,6-hexamethylenediame, 2-methyl-1,5-pentamethylenediamine,ethylenediamine, propylenediamine, diethylenetriamine, and the like)produced by injecting the amine into the cleavage mixture to neutralizethe liquid acid catalyst used. Feed 103 may further comprise olefinsheavier than cyclohexanone such as phenylcyclohexene isomers,hydroxylcyclohexanone, cyclohexenone, and the like. Thecyclohexylbenzene hydroperoxide may be produced by aerobic oxidation ofcyclohexylbenzene in the presence of a catalyst such as NHPI asdescribed above. The cyclohexylbenzene may be produced byhydroalkylation of benzene in the presence of a hydrogenation/alkylationbi-functional catalyst as described above.

Thus, feed 103 (the first mixture) may comprise, based on the totalweight thereof:

-   -   cyclohexanone at a concentration of Cxnone(FM1) in a range from        x11 wt % to x12 wt %, where x11 and x12 can be, independently:        10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82,        84, 85, 86, 88, or 90, as long as x11<x12; preferably, 20 wt        %≦Cxnone(FM1)≦30 wt %;    -   phenol at a concentration of Cphol(FM1) in a range from x21 wt %        to x22 wt %, where x21 and x22 can be, independently: 10, 15,        20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 85,        86, 88, or 90, as long as x21<x22; preferably, 20 wt        %≦Cphol(FM1)≦30 wt %; preferably,        0.3≦Cxnone(FM1)/Cphol(FM1)≦2.0; more preferably        0.5≦Cxnone(FM1)/Cphol(FM1)≦1.5; even more preferably        0.8≦Cxnone(FM1)/Cphol(FM1)≦1.2;    -   cyclohexylbenzene at a concentration of Cchb(FM1) in a range        from x31 wt % to x32 wt %, where x31 and x32 can be,        independently: 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4,        5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28,        30, 32, 34, 35, 36, 38, 40, 42, 44, 45, 46, 48, 50, 52, 54, 55,        56, 58, 60, 62, 64, 65, 66, 68, 70, 72, 74, 75, 76, 77, 78, 79,        or 80, as long as x31≦x32; preferably 30 wt %≦Cchb(FM1)≦60 wt %;    -   bicyclohexane at a concentration of Cbch(FM1) in a range from        x41 wt % to x42 wt %, where x41 and x42 can be, independently:        0, 0.00001, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, 0.5,        1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, 22, 24,        25, 26, 28, or 30, as long as x41<x42; preferably, 0.001 wt        %≦Cbch(FM1)≦1 wt %; and    -   light components (e.g., benzoic acid, and other carboxylic acids        comprising 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms), S-containing        compounds, and N-containing compounds each at a concentration of        Clc(FM1) in a range from x51 ppm to x52 ppm, where x51 and x52        can be, independently, 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7,        0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70,        80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000,        3000, 4000, 5000, 6000, 7000, 8000, 9000, or 10,000, as long as        x51<x52, preferably 1 ppm≦Clc(FM1)≦5000.

From the first distillation column T1, a first upper effluent 105comprising a portion of the cyclohexanone and a portion of lightcomponents such as water, methylcyclopentanone, and the like, isproduced in the vicinity of the top of the column T1. Effluent 105 maycomprise, based on the total weight thereof:

-   -   cyclohexanone at a concentration of Cxnone(UE1), where z11 wt        %≦Cxnone(UE1)≦z12 wt %, z11 and z12 can be, independently: 60,        65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99,        99.5, or 99.9, as long as z11<z12; preferably 75≦Cxnone(UE1)≦95;    -   phenol at a concentration of Cphol(UE1), where        z21≦Cphol(UE1)≦z22, z21 and z22 can be, independently: 0,        0.00001, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1,        0.5, or 1, as long as z21<z22;    -   cyclohexylbenzene at a concentration of Cchb(UE1), where y31 wt        %≦Cchb(UE1)≦y32 wt %, where y31 and y32 can be, independently:        0, 0.00001, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05,        0.1, 0.5, or 1, as long as y31<y32;    -   bicyclohexane at a concentration of Cbch(UE1), where y41 wt        %≦Cbch(UE1)≦y42 wt %, y41 and y42 can be, independently: 0,        0.00001, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1,        0.5, or 1, as long as y41<y42;    -   cyclohexanol at a concentration of Cxnol(UE1), where z51 wt        %≦Cxnol(UE1)≦z52 wt %, based on the total weight of the first        upper effluent, where z51 and z52 can be, independently: 0.001,        0.005, 0.01, 0.05, 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0,        4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, or 10, as        long as z51<z52; preferably 0.1 wt %≦Cxnol(UE1)≦5.0 wt %; and    -   light components at a total concentration of Clc(UE1), where a61        wt %≦Clc(UE1)≦a62 wt %, where a61 and a62 can be, independently:        0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0,        3.5, 4.0, 4.5, or 5.0, as long as a61<a62; preferably 0.001 wt        %≦Clc(UE1)≦1.0 wt %.

The first upper effluent 105 is then sent to a cyclohexanonepurification column T2, from which a third upper effluent 121 comprisinglight components such as water, methylcyclopentanone, and the like, isproduced at a location in the vicinity of the top of column T2 and thendelivered to storage S5. A second upper effluent 123 comprisingessentially pure cyclohexanone is produced and sent to storage S7. Inthe vicinity of the bottom of column T2, a second lower effluent 125 isproduced and delivered to storage S9. The second lower effluent can be,e.g., a KA oil comprising both cyclohexanone and cyclohexanol. Thus, thesecond upper effluent 123 may comprise, based on the total weightthereof, cyclohexanone at a concentration of Cxnone(UE2), whereCxnone(UE2)≧y11 wt %, y11 can be 95, 95.5, 96, 96.5, 97, 97.5, 98, 98.5,99, 99.5, 99.8, or 99.9. The second lower effluent 125 may comprise,based on the total weight thereof: cyclohexanol at a concentration ofCxnol(LE2), y51 wt %≦Cxnol(LE2)≦y52 wt %, y51 and y52 can be,independently: 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, 32,34, 35, 36, 38, 40, 42, 44, 45, 46, 48, 50, 52, 54, 55, 56, 58, 60, 62,64, 65, 66, 68, 70, 72, 74, 75, 76, 78, or 80, as long as y51<y52; andcyclohexanone at a concentration of Cxnone(LE2), e11 wt %≦Cxnol(LE2)≦e12wt %, e11 and e12 can be, independently: 10, 12, 14, 15, 16, 18, 20, 22,24, 25, 26, 28, 30, 32, 34, 35, 36, 38, 40, 42, 44, 45, 46, 48, 50, 52,54, 55, 56, 58, 60, 62, 64, 65, 66, 68, 70, 72, 74, 75, 76, 78, or 80,as long as e11<e12.

The first middle effluent 107 produced from the first distillationcolumn T1 comprises phenol at a concentration higher than in feed 103and higher than in the first upper effluent 105, cyclohexanone at aconcentration lower than in both feed 103 and the first upper effluent105, cyclohexylbenzene at a concentration desirably lower than in feed103 and higher than in the first upper effluent 105, and one or more ofother impurities such as bicyclohexane and cyclohexenone. Thus, effluent107 may comprise, based on total weight thereof:

-   -   cyclohexanone at a concentration of Cxnone(ME1), where a11 wt        %≦Cxnone(ME1)≦a12 wt %, a11 and a12 can be, independently: 1, 2,        4, 5, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30,        35, 40, 45, or 50, as long as a11<a12;    -   phenol at a concentration of Cphol(ME1), where a21 wt        %≦Cphol(ME1)≦a22 wt %, based on the total weight of the first        middle effluent, where a21 and a22 can be, independently: 10,        15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, as long        as a21<a22; preferably, 1.0≦Cphol(ME1)/Cxnone(ME1)≦3.0; more        preferably, 2.0≦Cphol(ME1)/Cxnone(ME1)≦3.0, close to the ratio        in a phenol/cyclohexanone azeotrope;    -   cyclohexylbenzene at a concentration of Cchb(ME1), where a31 wt        %≦Cchb(ME1)≦a32 wt %, a31 and a32 can be, independently: 0.001,        0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1, 2, 4, 5, 6,        8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, or 30, as        long as a31<a32;    -   bicyclohexane at a concentration of Cbch(ME1), where a41 wt        %≦Cbch(ME1)≦a42 wt %, a41 and a42 can be, independently: 0.001,        0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1, 2, 4, 5, 6,        8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, or 30, as        long as a41<a42;    -   cyclohexanol at a concentration of Cxnol(ME1), where a51 wt        %≦Cbch(ME1)≦a52 wt %, a51 and a52 can be, independently: 0.01,        0.02, 0.04, 0.05, 0.06, 0.08, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1,        2, 4, 5, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28,        or 30, as long as a51<a52; preferably 0.01 wt %≦Cxnol(ME1)≦5 wt        %; and    -   light components (e.g., benzoic acid, and other organic acid        comprising 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms), S-containing        compounds, and N-containing compounds each at a concentration of        Clc(ME1), where a71 ppm≦Clc(UE1)≦a72 ppm, where a71 and a72 can        be, independently: 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8,        0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80,        90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000,        3000, 4000, 5000, as long as a71<a72, preferably 1        ppm≦Clc(FM1)≦1000.

Preferably, effluent 107 is essentially free of S-containing componentsthat may poison the hydrogenation catalyst used in the hydrogenationreactor(s). However, depending on the quality of feed 103, effluent 107may comprise S-containing components at concentrations capable ofleading to poisoning of the hydrogenation catalyst, as discussed above.In such case, the present invention (exemplified and illustrated inFIGS. 7 and 8 and described in detail below) may be advantageously usedto reduce the S-containing components from effluent 107 before it is fedinto the hydrogenation reactor as the whole or a portion of thehydrogenation feed.

Effluent 107, if containing S-containing components capable of poisoningthe hydrogenation catalyst at acceptable concentration(s), can bedirectly delivered to a hydrogenation reactor R1, where it is mixed witha hydrogen gas feed 112 comprising fresh make-up hydrogen stream 111from storage S3 and recycle hydrogen 117. The phenol contained in feed107 and hydrogen reacts with each other in the presence of a catalystbed 113 inside reactor R1 to produce cyclohexanone. Some of thecyclohexanone inside the reactor R1 reacts with hydrogen in the presenceof the catalyst bed 113 as well to produce cyclohexanol. In theexemplary process shown in FIG. 1, surplus hydrogen is fed into reactorR1. It is contemplated that a second phenol-containing stream (notshown), separate from and independent of effluent 107, may be fed intothe hydrogenation reactor R1. Such additional feed can advantageouslycontain phenol at a concentration of Cphol(FP), d21 wt %≦Cphol(FP)≦d22wt %, based on the total weight of the second phenol-containing stream,where d21 and d22 can be, independently: 50, 55, 60, 65, 70, 75, 80, 85,90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100, as long as d21<d22.Preferably, the second phenol-containing stream comprises substantiallypure phenol produced by any process, such as the conventional cumeneprocess, coal-based processes, and the like.

The total hydrogenation feed, including stream 107 and optionaladditional streams, delivered to the hydrogenation reactor R1, ifblended together before being fed into R1, may have an overallcomposition containing phenol at a concentration of Cphol(A),cyclohexanone at a concentration of Cxnone(A), cyclohexylbenzene at aconcentration of Cchb(A), and bicyclohexane at a concentration ofCbch(A), wherein the concentrations are in the following ranges, basedon the total weight of the hydrogenation feed:

a1 wt %≦Cxnone(A)≦a2 wt %, where a1 and a2 can be, independently: 0.1,0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 4, 5, 6, 8, 10, 12, 14,15, 16, 18, 20, 22, 24, 25, 26, 28, 30, 32, 34, 35, 36, 38, 40, 42, 44,45, 46, 48, 50, as long as a1<a2;

b1 wt %≦Cphol(A)≦b2 wt %, where b1 and b2 can be, independently: 10, 15,20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 85, 86, 88,90, 91, 92, 93, 94, 95, 96, 97, 98, or 99, as long as a21<a22;

-   -   c1 wt %≦Cchb(A)≦c2 wt %, where c1 and c2 can be, independently:        0.001, 0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1, 2, 4,        5, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, or 30,        as long as c1<c2; preferably, 1 wt %≦Cchb(A)≦20 wt %; and

d1 wt %≦Cbch(A)≦d2 wt %, where d1 and d2 can be, independently: 0.001,0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1, 2, 4, 5, 6, 8, 10,12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, or 30, as long as d1<d2;preferably, 1 wt %≦Cbch(A)<20 wt %.

In the hydrogenation reaction zone, the following reactions can takeplace, resulting in an increase of concentrations of cyclohexanone,cyclohexanol, and bicyclohexane, and a decrease of concentrations ofphenol, cyclohexanone, and cyclohexylbenzene:

Cyclohexanone may hydrogenate to make cyclohexanol in the hydrogenationreactor R1. Because the net effect of the reaction is an overallincrease of cyclohexanone concentration, this reaction is not includedin the above paragraph. Nonetheless, cyclohexanone can engage incompetition against phenol for hydrogen, which should be reduced orinhibited.

The total amount of hydrogen, including fresh, make-up hydrogen andrecycled hydrogen, fed into the reactor R1, and the total amount ofphenol fed into the hydrogenation reaction zone desirably exhibit ahydrogen to phenol molar ratio of R(H2/phol), where R1≦R(H2/phol)≦R2, R1and R2 can be, independently: 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5,5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, or 10, as long R1<R2.While a higher R(H2/phol) ratio can result in higher overall conversionof phenol, it tends to result in higher conversion of cyclohexanone,higher selectivity of phenol to cyclohexanol, and higher conversion ofcyclohexylbenzene, as well. Therefore, it is generally desirable that inthe hydrogenation reactor R1, the reaction conditions, including but notlimited to temperature, pressure, and R(H2/phol) ratio, and catalysts,are chosen such that the overall conversion of phenol is not too high.

The hydrogenation reactions take place in the presence of ahydrogenation catalyst. The hydrogenation catalyst may comprise ahydrogenation metal performing a hydrogenation function supported on asupport material. The hydrogenation metal can be, e.g., Fe, Co, Ni, Ru,Rh, Pd, Ag, Re, Os, Ir, and Pt, and mixtures and combinations of one ormore thereof. The support material can be advantageously an inorganicmaterial, such as oxides, glasses, ceramics, molecular sieves, and thelike. For example, the support material can be activated carbon, Al₂O₃,Ga₂O₃, SiO₂, GeO₂, SnO, SnO₂, TiO₂, ZrO₂, Sc₂O₃, Y₂O₃, alkali metaloxides, alkaline earth metal oxides, and mixtures, combinations,complexes, and compounds thereof. The concentration of the hydrogenationmetal can be, e.g., in a range from Cm1 wt % to Cm2 wt %, based on thetotal weight of the catalyst, where Cm1 and Cm2 can be, independently:0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0,4.5, 5.0, as long as Cm1<Cm2.

Without intending to be bound by any particular theory, it is believedthat the above hydrogenation reactions occur quickly in the presence ofthe hydrogenation metal. Therefore, it is highly desirable that thehydrogenation metal is preferentially distributed in the outer rim ofthe catalyst particles, i.e., the concentration of the hydrogenationmetal in the catalyst particle surface layer is higher than in the corethereof. Such rimmed catalyst can reduce the overall hydrogenation metalloading, reducing cost thereof, especially if the hydrogenation metalcomprises a precious metal such as Pt, Pd, Ir, Rh, and the like. The lowconcentration of hydrogenation metal in the core of the catalystparticle also leads to a lower chance of hydrogenation of cyclohexanone,which may diffuse from the surface to the core of the catalystparticles, resulting in higher selectivity of cyclohexanone in theoverall process.

Certain light components, such as organic acids (e.g., formic acid,acetic acid, propanoic acid, linear, linear branched and cycliccarboxylic acids comprising 5, 6, 7, or 8 carbon atoms such as benzoicacid), N-containing compounds (e.g., amines, imides, amides,NO₂-substituted organic compounds), and S-containing compounds (e.g.,sulfides, sulfites, sulfates, sulfones, SO₃, SO₂), if contained in thereaction mixture in the hydrogenation reactor and allowed to contact thehydrogenation metal under the hydrogenation reaction conditions,poisoning of the hydrogenation catalyst can occur, leading to reductionof performance or premature failure of the catalyst. To avoid catalystpoisoning, it is highly desirable that the hydrogenation feed comprisessuch S-containing components at low concentrations described above.

It is believed that the catalyst surface can have different degrees ofadsorption affinity to the different components in the reaction mediasuch as phenol, cyclohexanone, cyclohexanol, cyclohexenone,cyclohexylbenzene, and bicyclohexane. It is highly desired that thecatalyst surface has higher adsorption affinity to phenol than tocyclohexanone and cyclohexylbenzene. Such higher phenol adsorptionaffinity will give phenol competitive advantages in the reactions,resulting in higher selectivity to cyclohexanone, lower selectivity ofcyclohexanol, and lower conversion of cyclohexylbenzene, which are alldesired in a process designed for making cyclohexanone. In addition, inorder to favor the conversion of phenol to cyclohexanone over theconversion of cyclohexylbenzene to bicyclohexane and the conversion ofcyclohexanone to cyclohexanol, it is highly desired that the phenolconcentration in the reaction medium in the hydrogenation reactor R1 isrelatively high, so that phenol molecules occupy most of the activecatalyst surface area. Therefore, it is desired that the overallconversion of phenol in the reactor R1 is relatively low.

As such, it is desired that in the hydrogenation reactor R1, theselectivity of phenol to cyclohexanone is Sel(phol)a, the selectivity ofphenol to cyclohexanol is Sel(phol)b, and at least one of the followingconditions (i), (ii), (iii), and (iv) is met:

30%≦Con(phol)≦95%;  (i)

0.1%≦Con(chb)≦20%;  (ii)

80%≦Sel(phol)a≦99.9%; and  (iii)

0.1%≦Sel(phol)b≦20%.  (iv)

The feed(s) to the hydrogenation reactor R1 may further comprisecyclohexenone at a concentration of Cxenone(A), where e1 wt%≦Cxenone(A)≦e2 wt %, based on the total weight of the hydrogenationfeed, e1 and e2 can be, independently: 0.01, 0.02, 0.03, 0.04, 0.05,0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1,1.5, 2, 2.5, 3.5, 4, 4.5, or 5, as long as e1<e2. It is highly desiredthat in step (B), the conversion of cyclohexenone is Con(xenone),Con5%≦Con(xenone)≦Con6%, where Con5 and Con6 can be, independently: 85,86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, as long asCon5<Con6. Thus, a great majority of the cyclohexenone contained in thefeed(s) is converted into cyclohexanone in the hydrogenation reactor R1.

At the bottom of reactor R1, a hydrogenation reaction product stream 115comprising phenol at a concentration lower than in stream 107,cyclohexanone at a concentration higher than in stream 107,cyclohexylbenzene, bicyclohexane, and surplus hydrogen is taken. Stream115 may comprise, based on the total weight thereof:

-   -   Cyclohexanone at a concentration of Cxnone(HRP), where b11 wt        %≦Cxnone(HRP)≦b12 wt %, b11 and b12 can be, independently: 20,        25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, as long        as b11<b12;    -   Phenol at a concentration of Cphol(HRP), where b21 wt        %≦Cphol(HRP)≦b22 wt %, b21 and b22 can be, independently: 1, 2,        5, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, 40,        50, as long as b21<b22;    -   cyclohexylbenzene at a concentration of Cchb(HRP), where b31 wt        %≦Cchb(HRP)≦b32 wt %, b31 and b32 can be, independently: 0.001,        0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1, 2, 4, 5, 6,        8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, as long        as b31<b32;    -   bicyclohexane at a concentration of Cbch(HRP), where b41 wt        %≦Cbch(HRP)≦b42 wt %, b41 and b42 can be, independently: 0.001,        0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1, 2, 4, 5, 6,        8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, as long        as b41<b42; and    -   cyclohexanol at a concentration of Cxnol(HRP), where b51 wt        %≦Cxnol(HRP)≦b52 wt %, b51 and b52 can be, independently: 0.01,        0.02, 0.04, 0.05, 0.06, 0.08, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1,        2, 4, 5, 6, 8, 10, as long as b51<b52.

Preferably, at least one of the following criteria is met in thehydrogenation reaction product stream 115:

-   -   Ra31≦Cchb(ME1)/Cchb(HRP)≦Ra32, where Ra31 and Ra32 can be,        independently: 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.75,        0.80, 0.85, 0.90, 0.92, 0.94, 0.95, 0.96, 0.98, 1.00, 1.02,        1.04, 1.05, 1.06, 1.08, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35,        1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 3.00, 4.00, 5.00,        6.00, 7.00, 8.00, 9.00, or 10.0, as long as Ra31≦Ra32; more        preferably, 0.80≦Cchb(ME1)/Cchb(HRP)≦1.00, meaning that        cyclohexylbenzene concentration does not decrease significantly        in the hydrogenation reaction zone;    -   Ra41≦Cbch(HRP)/Cbch(ME1)≦Ra42, where Ra41 and Ra42 can be,        independently: 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.75,        0.80, 0.85, 0.90, 0.92, 0.94, 0.95, 0.96, 0.98, 1.00, 1.02,        1.04, 1.05, 1.06, 1.08, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35,        1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 3.00, 4.00, 5.00,        6.00, 7.00, 8.00, 9.00, or 10.0, as long as Ra41<Ra42;        preferably, 1.0≦Cbch(HRP)/Cbch(ME1)≦1.5, meaning that        bicyclohexane concentration does not increase significantly in        the hydrogenation reaction zone; and    -   Ra51≦Cxnol(HRP)/Cxnol(ME1)≦Ra52, where Ra51 and Ra52 can be,        independently: 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.75,        0.80, 0.85, 0.90, 0.92, 0.94, 0.95, 0.96, 0.98, 1.00, 1.02,        1.04, 1.05, 1.06, 1.08, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35,        1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 3.00, 4.00, 5.00,        6.00, 7.00, 8.00, 9.00, or 10.0, as long as Ra51<Ra52;        preferably, 1.0≦Cxnol(HRP)/Cxnol(ME1)≦1.5, meaning that        cyclohexanol concentration does not increase significantly in        the hydrogenation reaction zone.

Stream 115 is then delivered to a separation drum D1, where a vaporphase comprising a majority of the surplus hydrogen and a liquid phaseis obtained. The vapor phase can be recycled as stream 117 to reactor R1as part of the hydrogen supply, and the liquid phase 119 is recycled tothe first distillation column T1 at one or more side locations on columnT1, at least one of which is above the location where the first middleeffluent 107 is taken, but below the location where the first uppereffluent 105 is taken.

The first bottom effluent 109 obtained from the first distillationcolumn T1 comprises primarily heavy components such ascyclohexylbenzene, bicyclohexane, amine salts mentioned above, C18+, C12oxygenates, and C18+ oxygenates. This fraction is delivered to a heaviesdistillation column T3 (the third distillation column), from which afourth upper effluent 127 desirably comprising cyclohexylbenzene at aconcentration higher than C31 wt % and a lower effluent 129 areproduced, where C31 can be 80, 82, 84, 85, 86, 88, 90, 92, 94, 95, 96,98, or 99. Effluent 127 may be delivered to storage S11 and effluent 129to storage S13. Effluent 127 may further comprise olefins, primarilyphenylcyclohexene isomers, at a non-negligible amount. It may bedesirable to subject effluent 127 to hydrogenation to reduce olefinconcentrations, and subsequently recycle the hydrogenated effluent 127to an earlier step such as cyclohexylbenzene oxidation to convert atleast a portion of it to cyclohexylbenzene hydroperoxide, such that theoverall yield of the process is improved.

FIG. 2 is a schematic diagram showing a portion of a process/systemsimilar to the process/system shown in FIG. 1, but comprising modifiedfluid communications between and/or within the first distillation columnT1 and the hydrogenation reactor R1. In this figure, the hydrogenationreaction product 115 comprises residual hydrogen, as in the exampleshown in FIG. 1. Effluent 115 is first delivered into separation drumD1, where a hydrogen-rich vapor stream 117 a is obtained, compressed bya compressor 118, and then delivered to reactor R1 as a stream 117 btogether with fresh, make-up hydrogen stream 111 into reactor R1. Aliquid stream 119 is obtained from separation drum D1, then divided intomultiple streams (two recycle streams 119 a and 119 b shown in FIG. 2),recycled to two different locations on the side of column T1, one belowthe location where the first middle effluent 107 is taken (shown atapproximately the same level as feed 103), and the other above thelocation where the first middle effluent 107 is drawn. This modifiedrecycle fluid communication between the hydrogenation reactor R1 and thefirst distillation column T1 compared to FIG. 1 has surprisingadvantages. It was found that where the recycle liquid stream 119 is fedto one location only, such as at a location above the first middleeffluent 107, bicyclohexane is continuously produced in reactor R1 fromthe cyclohexylbenzene in stream 107, and then steadily accumulates incolumn T1 to such high concentration that a separate phase can form,interfering with effective product separation in column T1. On the otherhand, where the recycle stream 119 is recycled back to column T1 atmultiple locations on T1 (as shown in FIG. 2), the probability offorming a separate bicyclohexane phase inside T1 is drastically reducedor eliminated.

FIG. 3 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1 and 2 comprising modified fluidcommunications and/or heat transfer arrangement between and/or withinthe first distillation column T1 and the cyclohexanone purificationcolumn T2. In this figure, the hydrogenation reactor R1 and itsperipheral equipment are not shown. In this figure, the first middleeffluent 107 drawn from column T1 is divided into multiple streams (twostreams 107 a and 107 b shown), one of which (107 a) is delivered to thehydrogenation reactor R1 (not shown) as hydrogenation feed, and theother (107 b) to a heat exchanger 131 in fluid and thermal communicationwith the cyclohexanone purification column T2. In this figure, thebottom stream 125 (e.g., comprising a mixture of cyclohexanone andcyclohexanol) from column T2 is divided into three streams: stream 135which passes through heat exchanger 131 and is heated by stream 107 b;stream 139 which is heated by a heat exchanger 141 and then recycled tocolumn T2; and stream 145, which is delivered to storage S9 via pump147. Stream 107 b becomes a cooler stream 133 after passing through heatexchanger 131, and is then subsequently recycled to first distillationcolumn T1 at one or more locations, at least one of which is locatedabove the location where the first middle effluent 107 is drawn. A heatmanagement scheme as illustrated in FIG. 3 can significantly improve theenergy efficiency of the overall process and system.

FIG. 4 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1-3, but comprising a tubular heatexchanger-type hydrogenation reactor. This figure illustrates an examplewhere the hydrogenation reactor R1 operates under hydrogenationconditions such that a majority of the phenol and/or cyclohexylbenzenepresent in the reaction media inside the reactor R1 are in vapor phase.In this figure, the first middle effluent 107 taken from the firstdistillation column T1 is first combined with hydrogen feeds (includingfresh make-up hydrogen stream 111 and recycle hydrogen stream 117 b),heated by a heat exchanger 153 and then delivered to a tubularheat-exchanger type hydrogenation reaction R1 having hydrogenationcatalyst installed inside the tubes 157. A stream of cooling media 159such as cold water supplied from storage S11 passes through the shell ofthe exchanger/reactor R1 and exits the reactor R1 as a warm stream 161and is then delivered to storage S13, thereby a significant amount ofheat released from phenol hydrogenation reaction is carried away,maintaining the temperature inside the reactor R1 in a range from T1° C.to T2° C., and an absolute pressure inside the reactor R1 in a rangefrom P1 kPa to P2 kPa, where T1 and T2 can be, independently: 140, 145,150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215,220, 225, 230, 235, 240, 250, 260, 270, 280, 290, 300, as long as T1<T2,and P1 and P2 can be, independently: 100, 110, 120, 130, 140, 150, 160,170, 180, 190, 200, 250, 300, 350, or 400, as long as P1<P2. PreferablyT2=240 and P2=200. Alternatively, the cooling medium may comprise atleast a portion of the hydrogenation feed in liquid phase, such that atleast a portion of the feed is vaporized, and at least a portion of thevapor feed is then fed to the hydrogenation reactor R1.

Because heat transfer of a vapor phase is not as efficient as a liquidphase, and the phenol hydrogenation reaction is highly exothermic, it ishighly desired that heat transfer is carefully managed in such vaporphase hydrogenation reactor. Other types of reactors suitable for aliquid phase reaction can be used as well. For example, fixed-bedreactors configured to have intercooling capability and/or quenchingoptions, so that the heat generated in the reaction can be taken awaysufficiently quickly to maintain the reaction media in a desirabletemperature range.

FIG. 5 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1-4, but comprising three fixed bedhydrogenation reactors R3, R5, and R7 connected in series. This figureillustrates an example where the hydrogenation reactors operate underhydrogenation conditions such that a majority of the phenol and/orcyclohexylbenzene present in the reaction media inside the reactors R3,R5, and R7 are in liquid phase. In this figure, the first middleeffluent 107 taken from the first distillation column T1 is firstcombined with hydrogen feeds (including fresh make-up hydrogen stream111 and recycle hydrogen stream 117 b) to form a feed stream 151, thenheated by a heat exchanger 153, and then delivered as stream 155 to afirst hydrogenation reactor R3 having a catalyst bed 167 inside. Aportion of the phenol is converted to cyclohexanone in reactor R3,releasing a moderate amount of heat raising the temperature of thereaction media. Effluent 169 exiting reactor R3 is then cooled down byheat exchanger 171, and then delivered into a second fixed bed reactorR5 having a catalyst bed 175 inside. A portion of the phenol containedin the reaction media is converted to cyclohexanone in reactor R5,releasing a moderate amount of heat raising the temperature inside thereactor R5. Effluent 177 exiting reactor R5 is then cooled down by heatexchanger 179, and then delivered to a third fixed bed hydrogenationreactor R7 having a catalyst bed 183 inside. A portion of the phenolcontained in the reaction media is converted to cyclohexanone in reactorR7, releasing a moderate amount of heat raising the temperature insidethe reactor R7. Effluent 185 exiting reactor R7 is then cooled down byheat exchanger 187, and delivered to drum D1, where a vapor phase 117 aand a liquid phase 119 are obtained. By using multiple reactors in thehydrogenation reaction zone, and the use of heat exchangers betweenadjacent reactors and after each reactor, temperatures inside thereactors R3, R5, and R7 are each independently maintained in a rangefrom T3° C. to T4° C., and the absolute pressures inside reactors R3,R5, and R7 are each independently maintained in a range from P3 kPa toP4 kPa, where T3 and T4 can be, independently: 140, 145, 150, 155, 160,165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230,235, 240, 250, 260, 270, 280, 290, 300, as long as T3<T4, and P3 and P4can be, independently: 375, 400, 425, 450, 475, 500, 525, 550, 575, 600,625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950,975, 1000, 1025, 1050, 1075, 1100, 1125, 1134, 1150, 1175, 1200, as longas P3<P4. Preferably, T4=240 and P4=1134. In general, higher temperaturefavors the production of cyclohexanol over cyclohexanone. Thus, it ishighly desirable that the hydrogenation is conducted at a temperature nohigher than 220° C.

FIG. 6 is a schematic diagram showing a portion of a process/systemsimilar to the process/system shown in FIGS. 1-5, but comprisingmodified fluid communications between and/or within the firstdistillation column T1 and the hydrogenation reactor R1. In this figure,two middle effluents, including a first middle effluent 107 a and asecond middle effluent 107 b, are drawn from the side of the firstdistillation column T1. The two effluents 107 a and 107 b have differingcompositions, and are combined to form a feed 107, which is thencombined with hydrogen feed streams 111 and 117 b and delivered to thehydrogenation reactor(s). Drawing two middle effluents with differentcompositions at different locations have unexpected technicaladvantages. It was found that if only one middle effluent is drawn froma single location on column T1, certain undesirable components, such ashydroxycyclohexanone(s), can accumulate in column T1. It is believedthat hydroxycyclohexanone(s) can undergo dehydration to formcyclohexenone, which can cause fouling inside column T1. By drawingmiddle effluents at different height locations on the column, one caneffectively reduce the accumulation of such undesirable components andthe probability of fouling inside the column.

FIG. 7 is a schematic diagram showing a portion of an exemplaryprocess/system of the present disclosure similar to those shown in FIGS.1-6, but comprising an anterior sorbent bed SBa before the firstdistillation column T1 configured for removing at least a portion of the5-containing components and/or the light components from a crude feed(crude mixture) to reduce or prevent catalyst poisoning in thehydrogenation reactor. A crude mixture feed stream 102 is first passedthrough the sorbent bed SBa, in which a basic solid-phase sorbentmaterial described above is installed. Alternatively, where the totalconcentration of the S-containing components and other light componentscapable of poisoning the hydrogenation catalyst in the crude mixturestream 102 is exceedingly high, an anterior stripper distillation column(not shown) may be used before the anterior sorbent bed SBa, so as toremove a portion of the light components and S-containing component fromthe first mixture fed into the first distillation column. Desirably,upon treatment by the anterior sorbent bed SBa, concentrations ofS-containing components capable of poisoning the hydrogenation catalystis reduced significantly in effluent 107 compared to in feed 102. Thus,in the embodiment shown in FIG. 7, assuming the total concentration ofS-containing components in feed 102 is Clc(cm), and the totalconcentration of S-containing components in effluent 107 is Clc(ME1),r1≦Clc(ME1)/Clc(cm)≦r2, where r1 and r2 can be, independently: 0.001,0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02,0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5,as long as r1<r2. Specifically, assuming the concentration of sulfuricacid in feed 102 is Cba(cm), and the total concentration of sulfuricacid in effluent 107 is Cba(ME1), r1≦Cba(ME1)/Cba(cm)≦r2, where r1 andr2 can be, independently: 0.001, 0.002, 0.003, 0.004, 0.005, 0.006,0.007, 0.008, 0.009, 0.01, 0.02, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07,0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, as long as r1<r2.

FIG. 8 shows an alternative to the configuration of FIG. 7. In thisfigure, instead of placing an anterior sorbent bed SBa before the firstdistillation column T1, a posterior sorbent bed SBp is placed behindcolumn T1, which receives the first middle effluent 107 as a feed,produces a a treated stream 195 depleted or low in such S-containingcomponents, which is delivered to the hydrogenation reactor as a portionor all of the hydrogenation feed 151 together with hydrogen feeds 111and 117 b. Alternatively, where the total concentration of theS-containing components in the first middle effluent 107 is exceedinglyhigh, a posterior stripper distillation column (not shown) may beinstalled before the sorbent bed SBp, and effluent 107 may be treated byboth the posterior stripper distillation column and the SBp before beingfed to the hydrogenation reactor R1 as at least a portion of thehydrogenation feed. Desirably, upon treatment, concentrations ofS-containing components capable of poisoning the hydrogenation catalystis reduced significantly in the hydrogenation feed compared to ineffluent 107. Thus, in the embodiment shown in FIG. 8, assuming thetotal concentration of S-containing components in the hydrogenation feedis Clc(hf), and the total concentration of S-containing components ineffluent 107 is Clc(ME1), r1≦Clc(hf)/Clc(ME1)≦r2, where r1 and r2 canbe, independently: 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007,0.008, 0.009, 0.01, 0.02, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08,0.09, 0.1, 0.2, 0.3, 0.4, 0.5, as long as r1≦r2. Specifically, assumingthe concentration of sulfuric acid in the hydrogenation feed is Cba(hf),and the total concentration of sulfuric acid in effluent 107 isCba(ME1), r1≦Cba(hf)/Cba(ME1)≦r2, where r1 and r2 can be, independently:0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01,0.02, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3,0.4, 0.5, as long as r1<r2.

If necessary, both of the anterior S-containing component removingmechanism described in connection with FIG. 7 (one or both of theanterior stripper distillation column and the anterior sorbent) and theposterior S-containing component removing mechanism described inconnection with FIG. 8 (one or both of the posterior stripperdistillation column and the posterior sorbent) may be used to preventthe S-containing components from entering into the hydrogenationreactor(s) at an unacceptably high concentration. The anterior andposterior sorbents can be the same or different, and may be selectedfrom: massive nickel; activated carbon, ion exchange resins (such asstrong and weak anion resins which are usually amine based), clay,kaolin, silica sorbents, alumina sorbents, molecular sieves, (i) oxidesof alkali metals, alkaline earth metals, and zinc; (ii) hydroxides ofalkali metals, alkaline earth metals, and zinc; (iii) carbonates ofalkali metals, alkaline earth metals, and zinc; (iv) bicarbonates ofalkali metals, alkaline earth metals, and zinc; (v) complexes of two ormore of (i), (ii), (iii), and (iv); (vi) solid amines; (vii)ion-exchange resins; and (viii) mixtures and combinations of two or moreof (i), (ii), (iii), (iv), (v), (vi), and (vii). The sorbents may removethe S-containing components by physical absorption or adsorption,extraction, and/or chemical reactions. Massive nickel is particularlyuseful for removing S-containing and N-containing poison components.However, a basic, solid-phase sorbent material such as those describedabove is preferable for removing sulfuric acid. A basic ion exchangeresin is particularly preferable for removing acid species and/orS-containing species.

Preferably, the hydrogenation feed thus treated by the anterior and/orposterior treatment(s) described in connection with FIG. 7 and/or FIG. 8may comprise the S-containing components at a total concentration in arange from Clc(hf)1 ppm to Ccl(hf)2 ppm by weight based on the totalweight of the hydrogenation feed, where Clc(hf)1 and Clc(hf)2 can be,independently, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09,0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 20, 30, 40, 50, 60, 70, 80, 90, or 100, as long asClc(hf)1<Clc(hf)2. Preferably, the hydrogenation feed thus treated bythe anterior and/or posterior treatment(s) described in connection withFIG. 7 and/or FIG. 8 may comprise the benzoic acid at a concentration ina range from Cba(hf)1 ppm to Cba(hf)2 ppm by weight based on the totalweight of the hydrogenation feed, where Cba(hf)1 and Cba(hf)2 can be,independently, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09,0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 20, 30, 40, 50, 60, 70, 80, 90, or 100, as long asClc(hf)1<Clc(hf)2.

FIG. 9 is a schematic diagram showing a portion of a process/systemsimilar to those shown in FIGS. 1-8 comprising a side stripper column T6after the cyclohexanone purification column T2, configured to reduceamounts of light components from the final cyclohexanone product. Inthis figure, the first upper effluent 105 comprising primarilycyclohexanone and light components obtained from the first distillationcolumn T1 and from the upper anterior stripper effluent, if any, isdelivered to cyclohexanone purification column T2, where three effluentsare obtained: a second upper effluent 121 rich in light components suchas water and methylcyclopentanone and depleted in cyclohexanone andcyclohexanol, a second middle effluent 123 rich in cyclohexanone anddepleted in light components and cyclohexanol, and a second lowereffluent 125 rich in cyclohexanol. Effluent 121 is first cooled down bya heat exchanger 197, then delivered to a separation drum D2 to obtain aliquid phase 199, which is recycled to column T2, and a vapor phase 201,which is cooled again by a heat exchanger 203, and delivered to anotherseparation drum D3 to obtain a liquid phase which is partly recycled asstream 205 to drum D2, and partly delivered to storage S5, and a vaporphase 206 which can be purged. Effluent 123 is delivered to a sidestripper T6 where the following streams are produced: a substantiallypure cyclohexanone stream 211 in the vicinity of the bottom thereof,which is delivered to a storage S7; and a light component stream 209,which is recycled to the column T2 at a location above 123.

In all of the above drawings, the phenol/cyclohexanone/cyclohexylbenzenehydrogenation feed delivered to the hydrogenation reactor is whollyobtained from one or more middle effluents from first distillationcolumn T1. However, it is contemplated that, additionally, a secondphenol feed stream comprising phenol at a concentration not lower thanthe feed obtained from column T1 can be fed to the hydrogenationreactor, either independently and separately or after being combinedwith the feed obtained from column T1 and/or hydrogen feed. For example,the second phenol stream may comprise substantially pure phenol having aphenol concentration, based on its total weight, of at least Cphol(f2)wt %, where Cphol(f2) can be, e.g., 80, 82, 84, 85, 86, 88, 90, 91, 92,93, 94, 95, 96, 97, 98, 99, 99.5, 99.8, or even 99.9.

Uses of Cyclohexanone and Phenol

The cyclohexanone produced through the processes disclosed herein may beused, for example, as an industrial solvent, as an activator inoxidation reactions and in the production of adipic acid, cyclohexanoneresins, cyclohexanone oxime, caprolactam, and nylons, such as nylon-6and nylon-6,6.

The phenol produced through the processes disclosed herein may be used,for example, to produce phenolic resins, bisphenol A, ε-caprolactam,adipic acid, and/or plasticizers.

While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention lends itself to variations notnecessarily illustrated herein. For this reason, then, reference shouldbe made solely to the appended claims for purposes of determining thetrue scope of the present invention.

The contents of all references cited herein are incorporated byreference in their entirety.

The present invention includes one or more of the following non-limitingaspects and/or embodiments.

EI-1. A process for making cyclohexanone, the process comprising:

(Ia) providing a crude mixture comprising cyclohexanone, phenol,cyclohexylbenzene, and an S-containing component;

(Ib) contacting the crude mixture with an anterior sorbent capable ofremoving at least a portion of the S-containing component to obtain afirst mixture comprising cyclohexanone, phenol, and cyclohexylbenzene;

(Ic) feeding the first mixture into a first distillation column;

(II) obtaining from the first distillation column:

a first upper effluent comprising cyclohexanone at a concentrationhigher than the first mixture;

a first middle effluent comprising phenol at a concentration higher thanthe first mixture, cyclohexanone, cyclohexylbenzene, and bicyclohexane;and

a first lower effluent comprising cyclohexylbenzene at a concentrationhigher than the first mixture;

(III) providing hydrogen and at least a portion of the first middleeffluent as at least a portion of a hydrogenation feed to ahydrogenation reaction zone;

(IV) contacting the hydrogenation feed with hydrogen in thehydrogenation reaction zone where phenol reacts with hydrogen in thepresence of a hydrogenation catalyst under hydrogenation reactionconditions to obtain a hydrogenation reaction product comprisingcyclohexanone at a concentration higher than the hydrogenation feed,phenol at a concentration lower than the hydrogenation feed,cyclohexylbenzene, and bicyclohexane; and

-   -   (V) feeding at least a portion of the hydrogenation reaction        product into the first distillation column.

EI-2. The process of EI-1, wherein the anterior sorbent in step (Ib)comprises a solid-phase basic material selected from: (i) oxides ofalkali metals, alkaline earth metals, and zinc; (ii) hydroxides ofalkali metals, alkaline earth metals, and zinc; (iii) carbonates ofalkali metals, alkaline earth metals, and zinc; (iv) bicarbonates ofalkali metals, alkaline earth metals, and zinc; (v) complexes of two ormore of (i), (ii), (iii), and (iv); (vi) solid amines; (vii)ion-exchange resins; and (viii) mixtures and combinations of two or moreof (i), (ii), (iii), (iv), (v), (vi), and (vii).

EI-3. The process of EI-1 or EI-2, wherein the S-containing componentcomprises SO₃, HSO₄ ⁻, R—HSO₄ and/or sulfuric acid.

EI-4. The process of any of EI-1 to EI-3, wherein the concentration ofthe S-containing component in the crude mixture is in a range from 10ppm to 10,000 ppm by weight based on the total weight of the crudemixture.

EI-5. The process of any of EI-1 to EI-4, wherein the concentration ofthe S-containing component in the first middle effluent is in a rangefrom 1 ppm to 1,000 ppm by weight based on the total weight of the firstmiddle effluent.

EI-6. The process of any of EI-1 to EI-5, wherein the concentration ofthe S-containing component in the hydrogenation feed is at most 100 ppmby weight based on the total weight of the hydrogenation feed.

EI-7. The process of any of EI-1 to EI-6, wherein the concentration ofthe S-containing component in the hydrogenation feed based on the totalweight of the hydrogenation feed is at most 10% of the concentration ofthe S-containing component in the crude mixture based on the totalweight of the crude mixture.

EI-8. The process of any of EI-1 to EI-7, wherein the hydrogenation feedcomprises:

cyclohexanone at a concentration in a range from 1 wt % to 50 wt %;

phenol at a concentration in a range from 10 wt % to 80 wt %;

cyclohexylbenzene at a concentration in a range from 0.001 wt % to 30 wt%; and

bicyclohexane at a concentration in a range from 0.001 wt % to 30 wt %,the percentages being based on the total weight of the hydrogenationfeed.

EI-9. The process of any of EI-1 to EI-8, wherein the crude mixturecomprises:

cyclohexanone at a concentration in a range from 10 wt % to 90 wt %;

phenol at a concentration in a range from 10 wt % to 80 wt %; andcyclohexylbenzene at a concentration in a range from 0.001 wt % to 75 wt%;

the percentages being based on the total weight of the crude mixture.

EI-10. The process of any of EI-1 to EI-9, wherein in step (IV), thehydrogenation catalyst comprises (i) a hydrogenation metal selected fromFe, Co, Ni, Ru, Rh, Pd, Ag, Re, Os, Ir, and Pt at a concentration in arange from 0.001 wt % to 5.0 wt %, based on the total weight of thecatalyst; and (ii) an inorganic support material selected from activatedcarbon, Al₂O₃, Ga₂O₃, SiO₂, GeO₂, SnO, SnO₂, TiO₂, ZrO₂, Sc₂O₃, Y₂O₃,alkali metal oxides, alkaline earth metal oxides, and mixtures,combinations, complexes and compounds thereof.

EI-11. The process of any of EI-1 to EI-10, wherein the first uppereffluent comprises the sulfur-containing component at a concentration ofno greater than 50 ppm by weight, based on the total weight of the firstupper effluent.

EI-12. The process of any of EI-1 to EI-11, wherein the first uppereffluent comprises the sulfur-containing component at a concentrationbased on the total weight of the first upper effluent no greater than10% than the concentration of the sulfur-containing component in thefirst mixture based on the total weight of the first mixture.

EI-13. The process of any of EI-1 to EI-12, wherein the first uppereffluent further comprises cyclohexanol, and the process furthercomprises:

(VI) feeding at least a portion of the first upper effluent into asecond distillation column; and

(VII) obtaining the following from the second distillation column:

a second upper effluent comprising cyclohexanone at a concentrationhigher than the first upper effluent;

a third upper effluent at a location above the second upper effluent,the third upper effluent comprising components having normal boilingpoints lower than that of cyclohexanone; and

a second lower effluent comprising cyclohexanone at a concentrationlower than the first upper effluent, and cyclohexanol at a concentrationhigher than the first upper effluent.

EI-14. The process of any of EI-1 to EI-13, wherein step (III)comprises:

(IIIa) contacting at least a portion of the first middle effluent with aposterior sorbent capable of removing at least a portion of theS-containing component to obtain the hydrogenation feed.

EI-15. The process of EI-14, wherein the posterior sorbent comprises asolid-phase basic material selected from: (i) oxides of alkali metals,alkaline earth metals, and zinc; (ii) hydroxides of alkali metals,alkaline earth metals, and zinc; (iii) carbonates of alkali metals,alkaline earth metals, and zinc; (iv) bicarbonates of alkali metals,alkaline earth metals, and zinc; (v) complexes of two or more of (i),(ii), (iii), and (iv); (vi) solid amines; (vii) ion-exchange resins; and(viii) mixtures and combinations of two or more of (i), (ii), (iii),(iv), (v), (vi), and (vii).

EI-16. The process of any of EI-1 to EI-15, wherein the crude mixturecomprises sulfuric acid at a concentration in a range from 1 ppm to2,000 ppm by weight based on the total weight of the crude mixture.

EI-17. The process of any of EI-1 to EI-16, wherein the concentration ofthe sulfuric acid in the hydrogenation feed is at most 100 ppm by weightbased on the total weight of the hydrogenation feed.

EI-18. The process of any of EI-1 to EI-17, wherein the firstdistillation column operates at a temperature of at least 120° C.

EI-19. The process of any of EI-1 to EI-18, wherein the firstdistillation column operates at a temperature higher than thedisassociation temperature of at least one of the following: (i)1,5-pentane diamine sulfuric acid complex; (ii) 1-methyl-1,5-pentanediamine sulfuric acid complex; and (iii) 1,6-hexane diamine sulfuricacid complex.

EI-20. The process of EI-14 or EI-15, wherein the concentration of theS-containing component in the hydrogenation feed based on the totalweight of the hydrogenation feed is at most 10% of the concentration ofthe S-containing component in the first middle effluent based on thetotal weight of the first middle effluent.

EI-21. The process of any of EI-1 to EI-20, wherein in step (IV),hydrogen and phenol are fed into the hydrogenation reaction zone at ahydrogen to phenol molar ratio in a range from 1.0 to 10.

EI-22. The process of any of EI-1 to EI-21, wherein the crude mixture instep (Ia) is obtained by a cleavage process comprising a step ofcontacting a cleavage feed mixture comprising1-phenyl-1-cyclohexane-hydroperoxide and cyclohexylbenzene with an acidcatalyst in a cleavage reactor to obtain a cleavage reaction product.

EI-23. The process of EI-22, wherein the acid catalyst comprisessulfuric acid.

EI-24. The process of EI-23, wherein the cleavage feed mixture isobtained by:

(Ia-1) contacting benzene with hydrogen in the presence of ahydroalkylation catalyst under hydroalkylation conditions to produce ahydroalkylation product mixture comprising cyclohexylbenzene;

(Ia-2) contacting the cyclohexylbenzene with oxygen in the presence of acatalyst to produce an oxidation reaction product mixture comprising1-phenyl-1-cyclohexane-hydroperoxide; and

(Ia-3) providing the cleavage feed mixture from the oxidation reactionproduct mixture.

EII-1. A process for making cyclohexanone, the process comprising:

(I) feeding a first mixture comprising cyclohexanone, phenol,cyclohexylbenzene, and an S-containing component into a firstdistillation column;

(II) obtaining from the first distillation column:

a first upper effluent comprising cyclohexanone at a concentrationhigher than the first mixture;

a first middle effluent comprising phenol at a concentration higher thanthe first mixture, cyclohexanone, cyclohexylbenzene, bicyclohexane, anda portion of the S-containing component; and

a first lower effluent comprising cyclohexylbenzene at a concentrationhigher than the first mixture;

(III) removing at least a portion of the S-containing component from thefirst middle effluent to obtain a hydrogenation feed;

(IV) feeding at least a portion of the hydrogenation feed and hydrogeninto a hydrogenation reaction zone where phenol reacts with hydrogen inthe presence of a hydrogenation catalyst under hydrogenation reactionconditions to obtain a hydrogenation reaction product comprisingcyclohexanone at a concentration higher than the hydrogenation feed,phenol at a concentration lower than the hydrogenation feed,cyclohexylbenzene, and bicyclohexane; and

(V) feeding at least a portion of the hydrogenation reaction productinto the first distillation column.

EII-2. The process of EII-1, wherein the S-containing componentcomprises SO₃, HSO₄ ⁻, R—HSO₄ and/or sulfuric acid.

EII-3. The process of EII-1 or EII-2, wherein step (III) comprises:

(IIIa) contacting at least a portion of the first middle effluent with aposterior sorbent capable of removing at least a portion of theS-containing component to obtain the hydrogenation feed.

EII-4. The process of EII-3, wherein the posterior sorbent comprises asolid-phase basic material selected from: (i) oxides of alkali metals,alkaline earth metals, and zinc; (ii) hydroxides of alkali metals,alkaline earth metals, and zinc; (iii) carbonates of alkali metals,alkaline earth metals, and zinc; (iv) bicarbonates of alkali metals,alkaline earth metals, and zinc; (v) complexes of two or more of (i),(ii), (iii), and (iv); (vi) solid amines; (vii) ion-exchange resins; and(viii) mixtures and combinations of two or more of (i), (ii), (iii),(iv), (v), (vi), and (vii).

EII-5. The process of any of EII-1 to EII-4, wherein the hydrogenationfeed comprises:

cyclohexanone at a concentration in a range from 1 wt % to 50 wt %;

phenol at a concentration in a range from 10 wt % to 80 wt %;

cyclohexylbenzene at a concentration in a range from 0.001 wt % to 30 wt%; and

bicyclohexane at a concentration in a range from 0.001 wt % to 30 wt %,the percentages being based on the total weight of the hydrogenationfeed.

EII-6. The process of any of EII-1 to EII-5, wherein the first mixturecomprises:

cyclohexanone at a concentration in a range from 10 wt % to 90 wt %;

phenol at a concentration in a range from 10 wt % to 80 wt %; andcyclohexylbenzene at a concentration in a range from 0.001 wt % to 75 wt%;

the percentages being based on the total weight of the first mixture.

EII-7. The process of any of EII-1 to EII-6, wherein in step (IV), thehydrogenation catalyst comprises (i) a hydrogenation metal selected fromFe, Co, Ni, Ru, Rh, Pd, Ag, Re, Os, Ir, and Pt at a concentration in arange from 0.001 wt % to 5.0 wt %, based on the total weight of thecatalyst; and (ii) an inorganic support material selected from activatedcarbon, Al₂O₃, Ga₂O₃, SiO₂, GeO₂, SnO, SnO₂, TiO₂, ZrO₂, Sc₂O₃, Y₂O₃,alkali metal oxides, alkaline earth metal oxides, and mixtures,combinations, complexes and compounds thereof.

EII-8. The process of any of EII-1 to EII-7, wherein the first uppereffluent further comprises cyclohexanol, and the process furthercomprises:

(VI) feeding at least a portion of the first upper effluent into asecond distillation column; and

(VII) obtaining the following from the second distillation column:

a second upper effluent comprising cyclohexanone at a concentrationhigher than the first upper effluent;

a third upper effluent at a location above the second upper effluent,the third upper effluent comprising components having normal boilingpoints lower than that of cyclohexanone; and

a second lower effluent comprising cyclohexanone at a concentrationlower than the first upper effluent, and cyclohexanol at a concentrationhigher than the first upper effluent.

EII-9. The process of any of EII-1 to EII-8, wherein the concentrationof the S-containing component in the first middle effluent is in a rangefrom 1 ppm to 1,000 ppm by weight based on the total weight of the firstmiddle effluent.

EII-10. The process of any of EII-1 to EII-9, wherein step (I)comprises:

(Ia) providing a crude mixture comprising cyclohexanone, phenol,cyclohexylbenzene, and the S-containing component;

(Ib) contacting the crude mixture with an anterior sorbent capable ofremoving at least a portion of the S-containing component to obtain thefirst mixture.

EII-11. The process of EII-10, wherein the anterior sorbent in step (Ib)comprises a solid-phase basic material selected from: (i) oxides ofalkali metals, alkaline earth metals, and zinc; (ii) hydroxides ofalkali metals, alkaline earth metals, and zinc; (iii) carbonates ofalkali metals, alkaline earth metals, and zinc; (iv) bicarbonates ofalkali metals, alkaline earth metals, and zinc; (v) complexes of two ormore of (i), (ii), (iii), and (iv); (vi) solid amines; (vii)ion-exchange resins; and (viii) mixtures and combinations of two or moreof (i), (ii), (iii), (iv), (v), (vi), and (vii).

EII-12. The process of any of EII-3 to EII-11, wherein the posteriorsorbent and/or the anterior sorbent comprise ion-exchange resins.

EII-13. The process of any of EII-10 to EII-12, wherein theconcentration of the S-containing component in the first middle effluentis in a range from 10 ppm to 1,000 ppm by weight based on the totalweight of the first middle effluent.

EII-14. The process of any of EII-10 to EII-13, wherein theconcentration of the S-containing component in the first middle effluentbased on the total weight of the middle effluent is at most 10% of theconcentration of the S-containing component in the crude mixture basedon the total weight of the crude mixture.

EII-15. The process of any of EII-10, EII-11, and EII-14, wherein thecrude mixture comprises sulfuric acid at a concentration in a range from1 ppm to 2,000 ppm by weight based on the total weight of the crudemixture.

EII-16. The process of any of EII-1 to EII-15, wherein the concentrationof the S-containing component in the hydrogenation feed is at most 100ppm by weight based on the total weight of the hydrogenation feed.

EII-17. The process of any of EII-1 to EII-16, wherein the firstdistillation column operates at a temperature of at least 120° C.

EII-18. The process of any of EII-1 to EII-17, wherein the firstdistillation column operates at a temperature higher than thedisassociation temperature of at least one of the following: (i)1,5-pentane diamine sulfuric acid complex; (ii) 1-methyl-1,5-pentanediamine sulfuric acid complex; and (iii) 1,6-hexane diamine sulfuricacid complex.

EII-19. The process of any of EII-1 to EII-18, wherein the concentrationof the S-containing component in the hydrogenation feed based on thetotal weight of the hydrogenation feed is at most 10% of theconcentration of the S-containing component in the first middleeffluent.

EII-20. The process of any of EII-1 to EII-19, wherein in step (IV),hydrogen and phenol are fed into the hydrogenation reaction zone at ahydrogen to phenol molar ratio in a range from 1.0 to 10.

EII-21. The process of any of EII-1 to EII-20, wherein the first mixturein step (I) is obtained by a cleavage process comprising a step ofcontacting a cleavage feed mixture comprising1-phenyl-1-cyclohexane-hydroperoxide and cyclohexylbenzene with an acidcatalyst in a cleavage reactor to obtain a cleavage reaction product.

EII-22. The process of EII-21, wherein the cleavage feed mixture isobtained by:

(Ia-1) contacting benzene with hydrogen in the presence of ahydroalkylation catalyst under hydroalkylation conditions to produce ahydroalkylation product mixture comprising cyclohexylbenzene;

(Ia-2) contacting the cyclohexylbenzene with oxygen in the presence of acatalyst to produce an oxidation reaction product mixture comprising1-phenyl-1-cyclohexane-hydroperoxide; and

(Ia-3) providing the cleavage feed mixture from the oxidation reactionproduct mixture.

1. A process for making cyclohexanone, the process comprising: (Ia)providing a crude mixture comprising cyclohexanone, phenol,cyclohexylbenzene, and an S-containing component; (Ib) contacting thecrude mixture with an anterior sorbent capable of removing at least aportion of the S-containing component to obtain a first mixturecomprising cyclohexanone, phenol, and cyclohexylbenzene; (Ic) feedingthe first mixture into a first distillation column; (II) obtaining fromthe first distillation column: a first upper effluent comprisingcyclohexanone at a concentration higher than the first mixture; a firstmiddle effluent comprising phenol at a concentration higher than thefirst mixture, cyclohexanone, cyclohexylbenzene, and bicyclohexane; anda first lower effluent comprising cyclohexylbenzene at a concentrationhigher than the first mixture; (III) providing hydrogen and at least aportion of the first middle effluent as at least a portion of ahydrogenation feed to a hydrogenation reaction zone; (IV) contacting thehydrogenation feed with hydrogen in the hydrogenation reaction zonewhere phenol reacts with hydrogen in the presence of a hydrogenationcatalyst under hydrogenation reaction conditions to obtain ahydrogenation reaction product comprising cyclohexanone at aconcentration higher than the hydrogenation feed, phenol at aconcentration lower than the hydrogenation feed, cyclohexylbenzene, andbicyclohexane; and (V) feeding at least a portion of the hydrogenationreaction product into the first distillation column.
 2. The process ofclaim 1, wherein the anterior sorbent in step (Ib) comprises asolid-phase basic material selected from: (i) oxides of alkali metals,alkaline earth metals, and zinc; (ii) hydroxides of alkali metals,alkaline earth metals, and zinc; (iii) carbonates of alkali metals,alkaline earth metals, and zinc; (iv) bicarbonates of alkali metals,alkaline earth metals, and zinc; (v) complexes of two or more of (i),(ii), (iii), and (iv); (vi) solid amines; (vii) ion-exchange resins; and(viii) mixtures and combinations of two or more thereof.
 3. The processof claim 1, wherein the S-containing component comprises SO₃, HSO₄ ⁻,R—HSO₄ and/or sulfuric acid.
 4. The process of claim 1, wherein theconcentration of the S-containing component in the crude mixture is in arange from 10 ppm to 10,000 ppm by weight based on the total weight ofthe crude mixture.
 5. The process of claim 1, wherein the concentrationof the S-containing component in the first middle effluent is in a rangefrom 1 ppm to 1,000 ppm by weight based on the total weight of the firstmiddle effluent.
 6. The process of claim 1, wherein the concentration ofthe S-containing component in the hydrogenation feed is at most 100 ppmby weight based on the total weight of the hydrogenation feed.
 7. Theprocess of claim 1, wherein the concentration of the S-containingcomponent in the hydrogenation feed based on the total weight of thehydrogenation feed is at most 10% of the concentration of theS-containing component in the crude mixture based on the total weight ofthe crude mixture.
 8. The process of claim 1, wherein the first uppereffluent comprises the sulfur-containing component at a concentration ofno greater than 50 ppm by weight, based on the total weight of the firstupper effluent.
 9. The process of claim 1, wherein step (III) comprises:(IIIa) contacting at least a portion of the first middle effluent with aposterior sorbent capable of removing at least a portion of theS-containing component to obtain the hydrogenation feed.
 10. The processof claim 9, wherein the posterior sorbent comprises a solid-phase basicmaterial selected from: (i) oxides of alkali metals, alkaline earthmetals, and zinc; (ii) hydroxides of alkali metals, alkaline earthmetals, and zinc; (iii) carbonates of alkali metals, alkaline earthmetals, and zinc; (iv) bicarbonates of alkali metals, alkaline earthmetals, and zinc; (v) complexes of two or more of (i), (ii), (iii), and(iv); (vi) solid amines; (vii) ion-exchange resins; and (viii) mixturesand combinations of two or more thereof.
 11. The process of claim 1,wherein the first distillation column operates at a temperature of atleast 120° C.
 12. The process of claim 1, wherein the first distillationcolumn operates at a temperature higher than the disassociationtemperature of at least one of the following: (i) 1,5-pentane diaminesulfuric acid complex; (ii) 1-methyl-1,5-pentane diamine sulfuric acidcomplex; and (iii) 1,6-hexane diamine sulfuric acid complex.
 13. Theprocess of claim 9, wherein the concentration of the S-containingcomponent in the hydrogenation feed based on the total weight of thehydrogenation feed is at most 10% of the concentration of theS-containing component in the first middle effluent based on the totalweight of the first middle effluent.
 14. A process for makingcyclohexanone, the process comprising: (I) feeding a first mixturecomprising cyclohexanone, phenol, cyclohexylbenzene, and an S-containingcomponent into a first distillation column; (II) obtaining from thefirst distillation column: a first upper effluent comprisingcyclohexanone at a concentration higher than the first mixture; a firstmiddle effluent comprising phenol at a concentration higher than thefirst mixture, cyclohexanone, cyclohexylbenzene, bicyclohexane, and aportion of the S-containing component; and a first lower effluentcomprising cyclohexylbenzene at a concentration higher than the firstmixture; (III) removing at least a portion of the S-containing componentfrom the first middle effluent to obtain a hydrogenation feed; (IV)feeding at least a portion of the hydrogenation feed and hydrogen into ahydrogenation reaction zone where phenol reacts with hydrogen in thepresence of a hydrogenation catalyst under hydrogenation reactionconditions to obtain a hydrogenation reaction product comprisingcyclohexanone at a concentration higher than the hydrogenation feed,phenol at a concentration lower than the hydrogenation feed,cyclohexylbenzene, and bicyclohexane; and (V) feeding at least a portionof the hydrogenation reaction product into the first distillationcolumn.
 15. The process of claim 14, wherein the S-containing componentcomprises SO₃, HSO₄ ⁻, R—HSO₄ and/or sulfuric acid.
 16. The process ofclaim 14, wherein step (III) comprises: (IIIa) contacting at least aportion of the first middle effluent with a posterior sorbent capable ofremoving at least a portion of the S-containing component to obtain thehydrogenation feed.
 17. The process of claim 16, wherein the posteriorsorbent comprises a solid-phase basic material selected from: (i) oxidesof alkali metals, alkaline earth metals, and zinc; (ii) hydroxides ofalkali metals, alkaline earth metals, and zinc; (iii) carbonates ofalkali metals, alkaline earth metals, and zinc; (iv) bicarbonates ofalkali metals, alkaline earth metals, and zinc; (v) complexes of two ormore of (i), (ii), (iii), and (iv); (vi) solid amines; (vii)ion-exchange resins; and (viii) mixtures and combinations of two or morethereof.
 18. The process of claim 14, wherein the concentration of theS-containing component in the first middle effluent is in a range from 1ppm to 1,000 ppm by weight based on the total weight of the first middleeffluent.
 19. The process of claim 14, wherein step (I) comprises: (Ia)providing a crude mixture comprising cyclohexanone, phenol,cyclohexylbenzene, and the S-containing component; (Ib) contacting thecrude mixture with an anterior sorbent capable of removing at least aportion of the S-containing component to obtain the first mixture. 20.The process of claim 19, wherein the anterior sorbent in step (Ib)comprises a solid-phase basic material selected from: (i) oxides ofalkali metals, alkaline earth metals, and zinc; (ii) hydroxides ofalkali metals, alkaline earth metals, and zinc; (iii) carbonates ofalkali metals, alkaline earth metals, and zinc; (iv) bicarbonates ofalkali metals, alkaline earth metals, and zinc; (v) complexes of two ormore of (i), (ii), (iii), and (iv); (vi) solid amines; (vii)ion-exchange resins; and (viii) mixtures and combinations of two or morethereof.
 21. The process of claim 16, wherein the posterior sorbentand/or the anterior sorbent comprise ion-exchange resins.
 22. Theprocess of claim 19, wherein the concentration of the S-containingcomponent in the first middle effluent is in a range from 10 ppm to1,000 ppm by weight based on the total weight of the first middleeffluent.
 23. The process of claim 14, wherein the crude mixturecomprises sulfuric acid at a concentration in a range from 1 ppm to2,000 ppm by weight based on the total weight of the crude mixture. 24.The process of claim 14, wherein the concentration of the S-containingcomponent in the hydrogenation feed is at most 100 ppm by weight basedon the total weight of the hydrogenation feed.
 25. The process of claim14, wherein the first distillation column operates at a temperature ofat least 120° C.